Liquid-phase monatomic catalyst capable of being produced on large scale and used for heterogeneous catalysis as well as catalysis method and application of liquid-phase monatomic catalyst

Abstract

The invention discloses a liquid-phase monatomic catalyst which can be produced on a large scale and is used for heterogeneous catalysis as well as a heterogeneous catalysis method and application of the liquid-phase monatomic catalyst. The liquid-phase monatomic catalyst is in a liquid state in which all substance components are mutually dissolved under reaction conditions and is used for directly performing interface contact catalytic reaction with reactants; the chemical components of the liquid-phase monatomic catalyst comprise at least two elements selected from transition metals, p-electron metals, rare earth metals, alkali metals, alkaline earth metals, metal aluminum and nonmetal elements such as sulfur, selenium and tellurium, wherein the outer layer is metal, rare earth metals, alkali metals, alkaline earth metals and metal aluminum; the chemical components are obtained from substance components, and the substance components are one or more of a mixture, a simple substance and an inorganic compound. The liquid-phase monatomic catalyst provided by the invention can realize low-cost large-scale preparation, is used for heterogeneous catalysis, has high activity and high efficiency, can realize effective separation of a product and the catalyst, has high stability, is not easy to inactivate and poisoning, and has extremely wide application.

Description

Technical Field

[0001] The present invention relates to the field of catalyst technology, and in particular to a liquid-phase single-atom catalyst that can be produced on a large scale, used for heterogeneous catalysis, and can achieve effective separation of products and catalysts, as well as a preparation method and application thereof. Background Art

[0002] Single-atom catalysis (SAC) is a research hotspot in catalysis. The ultimate limit for supported catalyst dispersion is the uniform distribution of the active species on the support in the form of single atoms. Therefore, single atoms represent the ideal state for supported catalysts. Single-atom catalysts are catalysts in which the active species component M exists on the support in the form of "isolated atoms" (without M-M bonds). Single-atom catalysts significantly improve the utilization efficiency of metal atoms, particularly precious metal atoms, with minimal metal loading. They can also alter the adsorption / desorption selectivity of the active species on the catalyst for different molecules, thereby accelerating reaction kinetics. Single-atom catalysts also combine the uniform, single active center characteristics of homogeneous catalysts with the structural stability and easy separation of heterogeneous catalysts. Furthermore, when particles are dispersed at the atomic level, the enormous surface energy, quantum size effects, unsaturated coordination environments, and metal-support interactions impart superior catalytic performance to single-atom catalysts. Today, the superior performance of single-atom catalysis (SAC) has become a distinct subfield of catalysis, much like superconductivity to electrical conductivity.

[0003] The inventors of this application have noted that when metal particles are reduced to the single-atom level, their specific surface area increases dramatically, leading to a dramatic increase in the metal's surface free energy. This makes it very easy for them to aggregate and couple to form large clusters during preparation and reaction, which in turn leads to the deactivation of the single-atom catalyst. Currently, the low-cost and large-scale preparation of single-atom catalysts (SACs) remains a major constraint: the cost of atomic-level dispersion of the catalyst and its loading on a substrate is extremely high, and increasing the loading is very difficult, posing a serious challenge to the large-scale application of single-atom catalysis methods. Most of the currently reported synthetic strategies can only produce gram- or even milligram-level products. For example, wet chemical co-precipitation and wet impregnation methods are simple to operate and have strong universality, showing development prospects for large-scale preparation. However, they face a major challenge in terms of scale-up. When catalysts are prepared under laboratory conditions, the synthesis conditions can be precisely controlled to obtain atomically dispersed metal catalysts. However, when scaled up to the synthesis ratio, uneven mass and heat transfer effects always exist, which can easily lead to localized concentration unevenness, thus causing metal agglomeration. For example, other methods such as mass separation soft landing require ultra-high vacuum preparation conditions, making them difficult to scale up. Atomic layer deposition (ALD) requires stringent operating conditions and equipment. Furthermore, preparation methods such as reverse Ostwald ripening and step-by-step reduction are still in the theoretical research stage. Furthermore, single-atom catalysts prepared using existing technologies suffer from poor stability during the reaction, and are prone to the risk of sintering and agglomeration.

[0004] On the other hand, most of the catalysts currently used in heterogeneous catalytic reactions use solid catalysts. The atoms on the solid surface of solid catalysts have clear positions and can only vibrate with small amplitudes around them. The surface is periodic, and the active sites for dissociative adsorption are few and fixed. Liquid catalysts, on the other hand, have mobile surface atoms and form many configurations with transient lifetimes. In addition, liquid atoms have higher mobility and can undergo larger displacements to accommodate the bonding "needs" of dissociated fragments. Therefore, liquid catalysts have more active sites, and unlike solid catalysts that are rapidly deactivated due to factors such as carbon deposition (coking), liquids provide a constantly updated gas-liquid interface and an environment for the continuous separation of by-products (such as solid carbon). In the past, liquid catalysts were mostly used in homogeneous catalytic reactions. In recent years, research and small-scale experiments on liquid metal LM in the field of heterogeneous catalysis have begun. However, the most common bubbling method has a relatively small catalytic area (for example, the general bubble size is 0.1-1 cm, while solid catalysts can often achieve particles or micropores with a diameter of 10-100 nm, a difference of 4-6 orders of magnitude). General liquid metal and alloy catalysts have not been applied on a large scale in industry because their activity is not enough to overcome the huge gap in catalytic area. Summary of the Invention

[0005] According to one embodiment of the present invention, an object is to provide a new form of single-atom catalyst, a liquid-phase single-atom catalyst that can be scalably produced for heterogeneous catalysis and effectively separates product from catalyst, as well as a preparation method and application thereof. The liquid-phase single-atom catalyst can be used for heterogeneous catalysis, can be scalably prepared, has high catalytic activity, is not easily deactivated, and has high stability.

[0006] The above purpose can be achieved by implementing the following technical solutions:

[0007] According to one aspect of the present invention, the present invention provides a liquid-phase single-atom catalyst for heterogeneous catalysis that can be scalably produced and can achieve effective separation of products and catalysts. The liquid-phase single-atom catalyst is in a liquid state in which all material components are mutually soluble under reaction conditions, and is used for direct interfacial contact catalytic reaction with reactants; the liquid-phase single-atom catalyst, its chemical composition includes at least two elements selected from transition metals, metals with p electrons in the outer layer, rare earth metals, alkali metals, alkaline earth metals, metallic aluminum, and non-metallic sulfur, selenium, and tellurium; the chemical composition is obtained from material components, and the material components are one or more of a mixture, a single substance, and an inorganic compound.

[0008] Optionally, the liquid-phase single-atom catalyst contains at least one chemical component element that exists in a transient quasi-ionic state in the liquid.

[0009] Optionally, the quasi-ionic state of the liquid-phase single-atom catalyst is manifested by the presence of non-integer Bader charges for at least two elements. For liquid-phase single-atom catalysts with different chemical compositions but at least one common element, or for liquid-phase single-atom catalysts with the same chemical composition but different contents, the smaller the absolute value of the Bader charge, the higher the catalytic activity. The Bader charge is obtained by subtracting the explicit electrons of the pseudopotential from the integrated electron density within the Bader volume when calculating the electronic properties of the molten alloy using quantum mechanics and ab initio molecular dynamics.

[0010] Optionally, the quasi-ionic state of the liquid-phase single-atom catalyst also exhibits an anomalous characteristic of having a resistivity different from that of the solid alloy. Further, optionally, the catalytic efficiency per unit catalytic area of ​​the liquid-phase single-atom catalyst is higher than that of the non-single-atom alloy catalyst. 3 ~10 8 times.

[0011] Optionally, the liquid-phase single-atom catalyst is in a liquid state in which all material components dissolve in each other under the reaction conditions, which is achieved by: dissolving into a liquid state at room temperature before the reaction, heating and melting into a liquid state before the reaction, or heating and melting into a liquid state under the reaction conditions.

[0012] Optionally, the liquid-phase single-atom catalyst is used for catalysis by direct interface contact with the reactants without adding other reagents.

[0013] Optionally, the transition metals include titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, yttrium, niobium, molybdenum, ruthenium, silver, cadmium, tungsten, rhenium, platinum, gold, and mercury. The metals with p-electrons in the outer shell include gallium, indium, tin, antimony, lead, and bismuth. The rare earth metals include lanthanum, cerium, praseodymium, neodymium, samarium, and europium. The alkali metals include lithium, sodium, potassium, rubidium, cesium, and francium. The alkaline earth metals include magnesium and calcium.

[0014] Optionally, the liquid-phase single-atom catalyst has a chemical composition of at least two elements selected from metal gallium, indium, tin, antimony, lead, and bismuth whose outer shells are p electrons.

[0015] Optionally, the liquid-phase single-atom catalyst comprises a first element and a second element. The second element is at least one element selected from the group consisting of p-electron metals such as gallium, indium, tin, antimony, lead, bismuth, and rare earth metals such as lanthanum, cerium, and samarium. The first element is at least one element selected from the group consisting of transition metals such as titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, molybdenum, ruthenium, silver, platinum, and gold; alkali metals such as lithium, sodium, and potassium; alkaline earth metals such as magnesium and calcium; and aluminum.

[0016] Further optionally, the proportion of the second element is not less than 35%.

[0017] Optionally, the first element is at least two selected from transition metals titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, molybdenum, ruthenium, silver, platinum, gold, alkali metals lithium, sodium, potassium, alkaline earth metals magnesium, calcium, and metal aluminum.

[0018] Optionally, the first element is selected from transition metals manganese, nickel, platinum, iron, silver, and ruthenium.

[0019] Optionally, the first element includes metallic manganese.

[0020] According to one aspect of the present invention, the present invention provides a multiphase catalytic method, in which, under reaction conditions, a liquid-phase single-atom catalyst and a reactant undergo an interfacial contact catalytic reaction, and after the reaction, the product, unreacted products and by-products are separated from the liquid-phase single-atom catalyst by density difference, and the separation is continuously carried out during the reaction so that the catalyst at the catalytic interface maintains reaction activity for a long time; wherein, under the reaction conditions, the reactant is a mixture of one or more of a gas, a solid and a liquid that is immiscible with the liquid-phase single-atom catalyst.

[0021] Optionally, when the reactant is a gas, the heterogeneous catalytic method further includes: using the liquid-phase single-atom catalyst as a continuous phase, allowing the gaseous reactant to enter the continuous phase in a bubbling form, and undergoing an interfacial contact catalytic reaction with the liquid-phase single-atom catalyst.

[0022] Optionally, when the reactant is solid, the heterogeneous catalytic method further includes: using the liquid-phase single-atom catalyst as a continuous phase, allowing the reactant to enter the continuous phase in the form of particles, suspend and / or disperse in the continuous phase, and undergo an interfacial contact catalytic reaction with the liquid-phase single-atom catalyst.

[0023] Optionally, when the reactant is a liquid, the heterogeneous catalysis method further comprises: introducing the reactant below the liquid surface of the liquid-phase single-atom catalyst to perform an interfacial contact catalytic reaction.

[0024] Optionally, the liquid-phase single-atom catalyst performs an interfacial contact catalytic reaction with the reactants in the form of droplets.

[0025] Optionally, the heterogeneous catalysis method includes: introducing the liquid-phase single-atom catalyst into the reaction container in the form of droplets by atomization; or, forming droplets of the liquid-phase single-atom catalyst in the reaction container by heating, evaporation and recondensation.

[0026] Optionally, the heterogeneous catalytic method includes: pre-preparing the liquid-phase single-atom catalyst or the material component that provides the chemical composition of the liquid-phase single-atom catalyst into an ultrafine powder, spraying the ultrafine powder into a reactor, and heating it under reaction conditions to form droplets.

[0027] Optionally, the heterogeneous catalytic method includes: first pre-loading the material components that provide the chemical composition of the liquid-phase single-atom catalyst on the surface of a solid carrier to obtain a carrier-loaded solid alloy catalyst; then introducing the carrier-loaded solid alloy catalyst into a reactor, and under reaction conditions, the material components on the surface of the solid carrier are heated and melted into droplets to form a liquid-phase single-atom catalyst loaded on the solid carrier.

[0028] Further optionally, the material components providing the chemical composition of the liquid-phase single-atom catalyst are pre-loaded on the surface of a solid carrier to obtain a carrier-loaded solid alloy catalyst, including: mixing the metal source, carrier and solvent of the material components to obtain a suspension; filtering the suspension and then drying it to obtain a precursor; calcining the precursor and then performing a reduction reaction in a reducing gas atmosphere to obtain a carrier-loaded solid alloy catalyst; the carrier-loaded solid alloy catalyst is introduced into the reactor by directly spraying it into the reactor or pre-filling it in the reactor in a fixed bed manner.

[0029] Optionally, the heterogeneous catalytic method further comprises: collecting the catalyst and separating it from impurities for reuse, wherein the catalyst refers to the droplets falling to the bottom of the reaction container after the reaction and / or the powder after cooling.

[0030] Optionally, the liquid-phase single-atom catalyst is a low-boiling-point liquid-phase single-atom catalyst, the chemical composition of which includes at least two low-boiling-point elements selected from transition metal mercury, zinc, alkali metal lithium, sodium, potassium, rubidium, cesium, and alkaline earth metal magnesium; and the liquid-phase single-atom catalyst in the reaction container is formed into droplets by heating, evaporating, and then condensing.

[0031] Furthermore, the low-boiling-point liquid-phase single-atom catalyst is heated, evaporated, and then condensed to form droplets in the reaction vessel, including the following steps: dividing the reaction vessel in the height direction into a bottom high-temperature zone, a middle main reaction zone, and an upper cooling zone in sequence; adding the liquid multiphase catalyst to the bottom high-temperature zone of the reaction vessel, and the low-boiling-point elements in the liquid multiphase catalyst are heated to low-boiling-point element vapor, and the low-boiling-point element vapor rises to the middle main reaction zone and the upper cooling transition zone and then condenses and atomizes into droplets, and refluxes and suspends under the combined action of gravity and the rising hot air flow, and finally falls from the upper cooling zone to the bottom high-temperature zone and is evaporated by the bottom high-temperature zone again, and the low-boiling-point elements are continuously evaporated, condensed, and atomized to form reflux droplets and are suspended in the middle main reaction zone of the reaction vessel; introducing the gaseous reactant into the middle main reaction zone and fully contacting with the reflux suspended droplets to cause a catalytic reaction.

[0032] Optionally, the heterogeneous catalytic method further includes: inserting an electrode into the liquid-phase single-atom catalyst and conducting or plasma-treating the gas reactants.

[0033] Optionally, the heterogeneous catalytic method further includes: mixing the solid catalyst particles with the gaseous reactants and bubbling them into the liquid single-atom catalyst continuous phase, wherein the gaseous reactants simultaneously catalyze the reaction with the liquid single-atom catalyst and the solid catalyst encapsulated in the bubbles.

[0034] Optionally, before performing heterogeneous catalysis, the method further includes: selecting a liquid-phase single-atom catalyst based on the absolute value of the Bader charge. Furthermore, selecting the liquid-phase single-atom catalyst based on the absolute value of the Bader charge. Still further, selecting the liquid-phase single-atom catalyst based on the absolute value of the Bader charge includes: determining the chemical composition of the liquid-phase single-atom catalyst based on the absolute value of the Bader charge, and determining the ratio of each element in the chemical composition based on the absolute value of the Bader charge.

[0035] According to another aspect of the present invention, the application of the liquid-phase single-atom catalyst provided by the present invention is applied to any reaction process of dehydrogenation reaction, hydrogenation reaction, olefin hydroformylation reaction, ammonia-related reaction, petroleum refining catalytic reaction, biomass catalytic utilization, organic pollutant treatment and polymer material regeneration.

[0036] Furthermore, the hydrogenation reaction includes: olefin hydrogenation and acetylene hydrogenation.

[0037] Furthermore, when the liquid-phase single-atom catalyst is used in a dehydrogenation reaction, the dehydrogenation reaction can be any one of methane thermal cracking, methane dry reforming, methane steam reforming, methane coupling to ethylene, methane oxygen-free coupling to aromatics, ethane dehydrogenation / oxidative dehydrogenation, propane dehydrogenation / oxidative dehydrogenation, C4 and above alkane dehydrogenation and oxidative dehydrogenation, ethylbenzene dehydrogenation, butane carbon dioxide coupling to light aromatics, and thermal cracking reactions of aromatic hydrocarbons, polyolefins, and asphalt.

[0038] Furthermore, when the liquid-phase single-atom catalyst is used in an ammonia-related reaction, the ammonia-related reaction is any one of ammonia decomposition, ammonia synthesis, ammonia oxidation, aniline production from nitrobenzene, and SCR denitration reaction.

[0039] Beneficial effect: The liquid-phase single-atom catalyst in the embodiment of the present invention is a new form of single-atom catalyst, and its chemical composition includes at least two elements selected from transition metals, metals with p electrons in the outer layer, rare earth metals, alkali metals, alkaline earth metals, metallic aluminum, and non-metallic sulfur, selenium, and tellurium elements, and under the reaction conditions, it is in a liquid state in which all material components dissolve in each other. Different from the currently known single-atom catalysts (solid state), the single-atom catalyst provided by the present invention is a liquid single-atom catalyst, which is a new form of single-atom catalyst that was previously unknown. The liquid single-atom catalyst is used to directly carry out interfacial contact catalysis with the reactants, and can be used for heterogeneous catalytic reactions with high catalytic activity and high catalytic efficiency. Moreover, the raw materials and preparation costs of the catalyst are low, it can be prepared on a large scale, it has good stability, it is not easy to be deactivated or poisoned during the reaction, and at the same time, the liquid-phase single-atom catalyst has a very wide range of applications, which provides a new idea for the selection of catalysts in the field of catalysis, especially in the field of heterogeneous catalysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 Schematic diagram of the structure of the device used in the heterogeneous catalytic reaction in one embodiment of the present invention.

[0041] Figure 2 Schematic diagram of the structure of the device used in the heterogeneous catalytic reaction in another embodiment of the present invention.

[0042] Figure 3 It is a schematic structural diagram of a quartz vent tube in a top-blown reactor device used in a heterogeneous catalytic reaction in one embodiment of the present invention.

[0043] Figure 4 1 is a schematic flow diagram of a heterogeneous catalytic reaction in one embodiment of the present invention. DETAILED DESCRIPTION

[0044] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, rather than all embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0045] As previously described, most of the catalysts currently used for heterogeneous catalytic reactions are non-single-atom solid catalysts, which have problems such as few and fixed active sites and low catalytic efficiency. The inventors recognized that when the surface is liquid, because the surface atoms are mobile and form many configurations with transient lifetimes; in addition, liquid atoms have higher mobility and can undergo larger displacements to accommodate the bonding "needs" of dissociated fragments; therefore, liquid heterogeneous catalysts will have more active sites; and, while solid catalysts are rapidly deactivated due to reasons including carbon deposition (coking), liquids can provide a continuously updated gas-liquid interface and an environment for the continuous separation of byproducts (such as solid carbon). However, currently available liquid catalysts are mostly used in homogeneous catalytic reactions. For example, homogeneous catalytic reactions usually need to be carried out under solvent conditions, such as water or organic reagents, which cannot meet the requirements of high-temperature working environments. For example, liquid metal LM heterogeneous catalysts that can work at high temperatures have a relatively small catalytic area when used using the most common bubbling method (for example, the size of bubbles is generally 0.1-1 cm, while conventional solid catalysts can often achieve particles or micropores with a diameter of 10-100 nm, a difference of 4-6 orders of magnitude). Since the activity of general liquid metal and alloy catalysts is not enough to overcome the huge gap in catalytic area, liquid heterogeneous catalysts cannot be used in many chemical reactions.

[0046] Although the newly developed solid-state supported single-atom catalysts (catalysts in the solid state under reaction conditions) in recent years can greatly improve the utilization efficiency of precious metal atoms with the lowest metal loading, have good molecular adsorption / desorption selectivity, the characteristics of uniform and single active centers of homogeneous catalysts and stable and easy-to-separate structures of heterogeneous catalysts, as well as excellent catalytic properties such as quantum size effect, unsaturated coordination environment and metal-support interaction; however, the inventors of the present application noticed that: for the solid-state supported single-atom catalyst, when the metal particles are reduced to the single-atom level, the specific surface area increases sharply, resulting in a sharp increase in the free energy of the metal surface, and it is very easy to agglomerate and couple to form large clusters during preparation and reaction, making it difficult to prepare at low cost and on a large scale, and it is also difficult to increase the loading amount. The liquid-phase single-atom catalyst of the present invention is a new form of single-atom catalyst different from the solid-state single-atom catalyst, which can overcome the above-mentioned problems of the solid-state single-atom catalyst.

[0047] The present invention provides a liquid-phase single-atom catalyst (LSAC) that can be produced on a large scale and is used for heterogeneous catalysis. Its chemical composition includes at least two elements selected from transition metals, metals with outer p-electrons, rare earth metals, alkali metals, alkaline earth metals, metallic aluminum, and non-metallic sulfur, selenium, and tellurium. The chemical composition is obtained from material components, and the material components are one or more of a mixture, a single substance, and an inorganic compound. The liquid-phase single-atom catalyst is in a liquid state under reaction conditions in which all material components are mutually soluble, and is used for direct interfacial contact catalytic reactions with reactants. The liquid-phase single-atom catalyst has good stability, is not easily deactivated or poisoned, has high catalytic activity and high catalytic efficiency, can be produced on a large scale, and is used for heterogeneous catalytic reactions by direct interfacial contact catalysis with reactants.

[0048] In the present invention, the liquid-phase single-atom catalyst has at least one element in a transient quasi-ionic state in the liquid. Through observation and theoretical calculation, it was found that at least some elements of the liquid-phase alloy catalyst are in a transient quasi-ionic and associated single-atom state during the ionization process, and have single-atom catalytic properties, that is, a liquid-phase single-atom catalyst. This quasi-ionic and associated single-atom state refers to the "short-range ordered" cluster structure of the liquid, in which there are several pairs of clusters (X, Y) that are subject to the combined effects of van der Waals forces, thermal motion, fluctuations, and mobile collisions, the valence bonds are destroyed, one cluster X in a pair of clusters is dissociated, and an element x of X is ionized, and the rest of this cluster X is associated as single atoms or free radicals, recorded as x'-X c , where x' represents a single anion or cation formed by the cluster X; X c The remaining associated single atoms or radicals of cluster X are represented by another cluster Y, which forms a corresponding cationic / anionic cluster Y'. Subsequently, X' and Y' recombine to form a neutral state. During the period between the dissociation and ionization of cluster X and its recombination, one of the elements exists in a discrete single ion state in the liquid. This, along with the associated single atoms / radicals, becomes a catalytically active center, and the corresponding molecular ion cluster simultaneously becomes another catalytically active center. Liquid-phase alloy catalysts characterized by the transient quasi-ionic state of some elements are known as liquid-phase single-atom catalysts (LSACs).

[0049] In the Bader charge test, the Bader charge of at least two elements in the liquid-phase single-atom catalyst is fractional, i.e., non-integer. Fractional charge is the result of transient ionization averaging. The Bader charge is obtained by subtracting the apparent electrons of the pseudopotential from the integrated electron density within the Bader volume when calculating the electronic properties of the molten alloy using quantum mechanics and ab initio molecular dynamics. Furthermore, in the Bader charge test, for liquid-phase single-atom catalysts with different chemical compositions (referring to liquid-phase single-atom catalysts with different chemical compositions but at least one element in common) or liquid-phase single-atom catalysts with the same chemical composition but different contents, the smaller the absolute value of the Bader charge, the higher the catalytic activity. Some elemental atoms / clusters have positive charges, such as gallium (Ga), indium (In), tin (Sn), lead (Pb), and bismuth (Bi); some atoms / clusters have negative charges, such as Mn, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, Ru, Ag, Pt, Au, La, Ce, Li, Na, K, Mg, Ca, and Al. Furthermore, based on these characteristics, when applying these liquid-phase single-atom catalysts to various fields, the Bader charge can be used to select the appropriate liquid-phase single-atom catalyst and determine / adjust its chemical composition and ratio. For example, by performing quantum mechanical calculations on the electronic properties of the liquid catalyst for various formulations, the formulation with the smallest absolute Bader charge value in the calculated results can be selected as the preferred formulation.

[0050] In addition, the liquid-phase single-atom catalyst has an anomalous characteristic that is different from the resistivity of the solid-state alloy. For example, under normal circumstances, the resistivity of the solid-state alloy increases with increasing temperature and increases with increasing high-resistivity metal content, while the resistivity of ionic liquids, including ionic compound melts, decreases with increasing temperature. However, the resistivity temperature coefficient of the liquid-phase single-atom catalyst in the present invention is abnormal, and even the resistivity of some liquid-phase single-atom catalysts decreases with increasing temperature. Conventional observations and existing theoretical models believe that alloy melts are not ordinary ionic liquids. Therefore, at least some of the elements in the above-mentioned molten binary alloy (liquid) are in a quasi-ionic state. In addition, the resistivity of the solid-state alloy decreases with increasing low-resistivity metal content, but the resistivity variation range of the liquid-phase single-atom catalyst deviates greatly from that of the solid-state alloy, and even the resistivity of some liquid-phase single-atom catalysts increases with increasing low-resistivity metal content within a certain composition range.

[0051] In addition, the catalytic efficiency per unit catalytic area is compared with that of the non-single-atom catalyst. 3 ~10 8times, the catalytic efficiency is greatly improved, and the liquid-phase single-atom catalyst has ultra-high catalytic performance. The inventors of this application specifically pointed out that it is based on a profound microscopic mechanism of certain liquid physics: some elements are in the state of quasi-ions and associated single atoms; the clusters are dissociated, the elements are ionized and monoatomic, and then recombined. Due to the above microscopic mechanism, the single ions, associated single atoms / free radicals, and corresponding molecular ion clusters in the reaction process all directly participate in the catalysis as active centers with "single-atom" characteristics. Unlike solid-state supported single-atom catalysts (solid-state supported single-atom catalysts have only a single single-atom active center), the LSACs of the present invention have so-called 3-active centers (i.e., single ions, associated single atoms / free radicals, and corresponding molecular ion clusters are all active centers), which can enhance and change the reaction mechanism by binding to intermediates to form so-called co-catalytic interactions. Therefore, the single-atom discreteness of LSACs is completely uniform and dynamically stable on a macroscopic scale. In addition to the atomic utilization efficiency, high selectivity, and high reaction kinetics of single-atom catalysis, LSACs possess the uniform active centers of homogeneous catalysts and the structural stability and easy separation of heterogeneous catalysts. They also possess quantum size effects, an unsaturated coordination environment, and strong active center-support interactions. The exceptionally high catalytic performance per unit catalytic area of ​​these catalysts confirms their single-atom catalytic properties.

[0052] Furthermore, existing catalytic theory holds that catalytic performance is primarily determined by the content of the catalytically active species, requiring the use of noble metals as active species in many reactions. However, due to the co-catalytic interactions (formed by the aforementioned physical mechanisms), many elements generally considered inert in the art (such as metals with p-electrons in their outer shells) exhibit strong catalytic activity in the liquid-phase single-atom catalysts (LSACs) of the present invention. Related examples of the present invention demonstrate that: 1) even combinations of low active metal content (such as Pt, Ni, and Mn) with high inert element content (such as Bi, Sn, and In) often exhibit high activity, and the catalytic activity of alloys of active metal and inert element melts can even exceed that of 100% active metal. 2) For some active metal and inert element combinations, increasing the inert element content actually improves catalytic activity. 3) Two elements, such as Bi and In, that are generally considered completely inert to certain reactions, also exhibit high catalytic activity. 4) Several catalytic experiments and simulations have shown that elements enriched on the surface of LSAC melts, often considered completely inert to the reaction, serve as active sites. For example, in the pyrolysis of methane in a Mn-Bi alloy melt, although pure Bi has very low catalytic activity, within the formulation range of LSACs, the electron-deficient Bi sites promote the dissociation of methane, allowing the methyl group to coordinate with a Bi atom (quasi-ion). The Mn quasi-ion and single-atom sites adsorb H, i.e., the 3-active center, all participate in catalysis. Thus, the liquid-phase single-atom catalysts described in the present invention greatly expand the range of available catalysts, avoiding the use of precious and toxic metals in many cases and achieving high catalytic efficiency using a combination of many low-cost elements. For example, because inert metal elements in the liquid-phase single-atom catalyst can also serve as catalytic active centers, the activity of the liquid-phase single-atom catalyst can be adjusted based on the inert metal content.

[0053] In addition, from the perspective of preparation cost and scalability, the cost of the liquid-phase single-atom catalyst LSACs is much lower than that of existing supported solid-phase single-atom catalysts, and it is also easy to prepare on a large scale. As we all know, in the solid phase, objects with large surface areas naturally have a tendency to agglomerate, and single atoms have the largest theoretical specific surface area. Therefore, the realization of solid-state supported single-atom catalysts requires overcoming huge surface energy to achieve atomic-level discreteness, which inevitably requires the use of complex and difficult preparation methods, high cost, difficulty in increasing the load, and difficulty in large-scale preparation. In addition, the prepared single-atom catalyst is prone to sintering and agglomeration during the reaction process, and has poor stability. It is obvious that the preparation method of the liquid-phase single-atom catalyst of the present invention is very simple. After determining the appropriate components and formula, simple process methods such as heating and melting can utilize the microscopic mechanism in the liquid phase given by nature to achieve natural "single atoms (including single ions)" uniform dispersion. Low cost and large-scale preparation are no longer problems. The single-atom catalytic properties remain good during the reaction, and there is no sintering and agglomeration. In addition, under the reaction conditions, the support of liquid droplet LSACs and supported solid catalysts is different, because in this case, the liquid droplet LSACs are liquid-phase single-atom catalyzed and achieved by a simple method; while supported solid catalysts are either not single-atom catalyzed or have the disadvantages of being difficult to prepare and unstable in the solid-state single-atom catalysis.

[0054] Furthermore, the liquid-phase single-atom catalyst is in a liquid state under the reaction conditions, and this state can be achieved in the following ways: it can be dissolved into a liquid state at room temperature before the reaction, and the interface contact reaction with the reactants can be carried out in the liquid state under the reaction conditions; it can also be heated and melted into a liquid state before the reaction, and the interface contact reaction can be carried out in the liquid state under the reaction conditions; it can also be heated and melted into a liquid state under the reaction conditions (i.e., while the catalytic reaction is proceeding) and the interface contact reaction can continue in the liquid state. For example, mercury and gallium in the chemical composition are in a liquid state at room temperature and can be dissolved into a liquid state at room temperature. When heating and melting are used to achieve the liquid state, the melting temperature can be controlled to be 2°C higher than the theoretical lowest melting point on the alloy phase diagram. The melting process is relatively mature and the melting temperature required for the liquid-phase single-atom catalyst described in the present invention is relatively low. Whether it is the above-mentioned room temperature dissolution or heating and melting method, the preparation process is simple, the conditions are mild, and it is convenient for large-scale production.

[0055] The liquid-phase single-atom catalysts described herein are used for heterogeneous chemical catalysis. Under reaction conditions, liquid LSACs and reactants come into interfacial contact within a reaction vessel, resulting in a catalytic reaction. During and after the reaction, the products, unreacted products, and by-products can be effectively separated from the LSACs. The reactants can be a mixture of one or more of a gas, a solid, or a liquid immiscible with the liquid-phase single-atom catalyst, and undergo interfacial heterogeneous catalysis with the liquid LSACs. For example, when the reactant is a gas, it can be introduced below the liquid surface of the liquid-phase single-atom catalyst to enable bubbling catalysis; or when it is a solid particle, it can sink or suspend in the liquid-phase single-atom catalyst. Furthermore, the liquid-phase single-atom catalyst can be catalyzed by direct interfacial contact with the reactants without the addition of any solvent, such as water, an organic solvent, or a salt solution. This overcomes the limitations of other solvents, such as the inability to withstand high-temperature working environments.

[0056] In addition, the chemical composition of the liquid-phase single-atom catalyst of the present invention may include transition metals such as titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, yttrium, niobium, molybdenum, ruthenium, silver, cadmium, tungsten, rhenium, platinum, gold, and mercury; metals with outer p electrons may include gallium, indium, tin, antimony, lead, and bismuth; rare earth metals may include lanthanum, cerium, praseodymium, neodymium, samarium, and europium; alkali metals may include lithium, sodium, potassium, rubidium, cesium, and francium; and alkaline earth metals may include magnesium and calcium.

[0057] In an optional embodiment, the liquid-phase single-atom catalyst has a chemical composition comprising a first element and a second element. The first element is at least one element selected from the group consisting of transition metals titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, molybdenum, ruthenium, silver, platinum, gold, alkali metals lithium, sodium, potassium, alkaline earth metals magnesium, calcium, and aluminum. The second element is at least one element selected from the group consisting of metals with p electrons in the outer shell, gallium, indium, tin, antimony, lead, bismuth, rare earth metals lanthanum, cerium, and samarium. The first element provides high catalytic activity, and the second element provides a low melting point and low price for the alloy to reduce costs, which is more conducive to large-scale preparation; due to the aforementioned co-catalytic interaction, in some combinations, the addition of the second element increases activity. Furthermore, the proportion of the second element is not less than 35%. The above proportion of the second element can provide a low melting point for the liquid-phase single-atom catalyst of the present invention, ensuring that it is in a liquid state under reaction conditions, and also reduces the conditions for achieving a liquid phase, which is more conducive to large-scale preparation. The second element content in the formulation should be moderate. If it is too low, it will not be able to form a liquid under the reaction conditions and will not undergo interfacial catalytic reactions with the reactants in the LSAC manner. Preferably, the second element accounts for no less than 65%. Due to the aforementioned co-catalytic interaction, increasing the second element content in some combinations also increases activity.

[0058] In addition, in some applications, the first element in the chemical composition of the liquid-phase single-atom catalyst is selected from the transition metals manganese, nickel, platinum, iron, silver, and ruthenium. This formula combination can provide the liquid-phase single-atom catalyst of the present invention with higher activity and improved catalytic efficiency. In some applications, the first element in the chemical composition of the liquid-phase single-atom catalyst is selected from at least one of the transition metals titanium, vanadium, chromium, cobalt, zinc, molybdenum, alkali metal lithium, alkaline earth metal magnesium, and metal aluminum. This formula combination liquid-phase single-atom catalyst can provide higher activity and improved catalytic efficiency in some catalytic reactions, while also having relatively low metal prices.

[0059] In a more preferred embodiment, the liquid-phase single-atom catalyst has at least two first elements in its chemical composition. That is, the first element is selected from at least two of the transition metals titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, molybdenum, ruthenium, silver, platinum, gold, alkali metals lithium, sodium, potassium, alkaline earth metals magnesium, calcium, and aluminum. The use of a formula combination of at least two first elements and at least one second element can bring into play the synergistic catalytic effect of multiple active metal elements and improve the catalytic efficiency. More preferably, the first element is selected from the transition metals manganese, nickel, platinum, iron, silver, and ruthenium. The above formula combination can provide the liquid-phase single-atom catalyst of the present invention with higher activity and improve the catalytic efficiency.

[0060] In a preferred embodiment, the liquid-phase single-atom catalyst comprises a first element and a second element, wherein the first element comprises at least metallic manganese. The liquid-phase single-atom catalyst is formed by combining manganese with one or more second elements, such as manganese-bismuth, manganese-lanthanum, manganese-cerium, manganese-samarium, manganese-cerium-bismuth, and manganese-bismuth-tin. Alternatively, the liquid-phase single-atom catalyst is formed by combining manganese and another first element with one or more second elements, such as manganese-copper-bismuth, manganese-lithium-bismuth, manganese-nickel-bismuth, and manganese-nickel-tin. In particular, when the first element contains manganese, the calculated absolute value of the non-integer Bader charge of the manganese alloy melt is smaller than that of alloy melts formed by traditional highly active catalysts such as platinum and nickel with the corresponding second element, and the catalytic activity for various classical reactions is also higher than that of traditional highly active catalysts. Furthermore, the alloy has a low melting point, especially the manganese-bismuth alloy, which allows for applications in catalytic reactions with lower reaction temperatures. Furthermore, the relatively low price of manganese (lower than that of non-ferrous metals such as copper and nickel, and significantly lower than that of precious metals) also contributes to cost reduction.

[0061] In another alternative embodiment, the liquid-phase single-atom catalyst comprises at least two of the following: gallium, indium, tin, antimony, lead, and bismuth, each containing a second element with p electrons in its outer shell; i.e., the first element is absent. This preferred combination of ingredients can provide higher activity and a lower alloy melting point, expanding the low-temperature application range of the liquid-phase single-atom catalyst of the present invention.

[0062] The present invention provides a heterogeneous catalytic method that can effectively separate products from catalysts. Under reaction conditions, the liquid-phase single-atom catalyst and reactants directly undergo an interfacial contact catalytic reaction. After the reaction, the product, unreacted products, and by-products are separated from the liquid-phase single-atom catalyst by density differences. This separation is performed continuously during the reaction, thereby avoiding the problem of solid catalyst deactivation due to coking and carbon deposition, or surface coating. Under the reaction conditions, the reactants are a mixture of one or more of a gas, a solid, and a liquid that is immiscible with the liquid-phase single-atom catalyst. The liquid-phase single-atom catalyst of the present invention enables heterogeneous catalysis. On the one hand, during the interfacial contact catalytic reaction, effective separation of products and catalysts is achieved based on density differences. For example, after the catalytic reaction occurs, effective separation is achieved based on the density difference between the other materials (low density) and the liquid LSACs (high density). Products, unreacted products, and byproducts (undissolved and / or supersaturated precipitated after dissolution) float to the surface or sink to the bottom of the container, effectively separating them from the liquid LSACs. Gaseous products naturally float to the surface, while solids / liquids float to the surface / sink to the bottom of the reaction vessel due to the density difference with the liquid LSACs. Furthermore, this separation occurs continuously during the reaction, and the liquid-phase single-atom catalyst maintains a high catalyst content (high stability), avoiding the problem of solid catalyst deactivation (the inevitable coating and accumulation of products and byproducts on the solid catalyst surface is a major cause of catalyst deactivation and poisoning).

[0063] In addition, when performing heterogeneous catalytic reactions, such as Figure 4 As shown, according to the state of the reactants, a suitable introduction method is adopted to introduce the reactants and the liquid-phase single-atom catalyst into the reactor; the reactants and the liquid-phase single-atom catalyst are allowed to perform a more effective interfacial contact reaction under the reaction conditions; after the reaction, the product, the unreacted product and the by-product are separated from the liquid-phase single-atom catalyst by the density difference, and the separation is continued during the reaction. Wherein, when the reactant is a gas, the liquid-phase single-atom catalyst can be used as a continuous phase, so that the gaseous reactant enters the continuous phase in the form of bubbles and performs an interfacial contact catalytic reaction with the liquid-phase single-atom catalyst. When the reactant is a solid, the liquid-phase single-atom catalyst is used as a continuous phase, so that the reactant is sprayed into the continuous phase in the form of particles, suspended or dispersed in the continuous phase, and performs an interfacial contact catalytic reaction with the liquid-phase single-atom catalyst. When the reactant is a liquid (immiscible with LSACs), the reactant is introduced into the liquid and / or on the liquid surface of the liquid-phase single-atom catalyst for an interfacial contact catalytic reaction. In addition, optionally, the heterogeneous catalytic reaction can also mechanically stir the catalyst and material in the reaction vessel or stir with an auxiliary airflow.

[0064] In a preferred embodiment, the liquid-phase single-atom catalyst is controlled to perform interfacial contact catalysis in the form of droplets. The average particle size of the droplets is controlled to be less than 0.1 mm; further, the particle size of the droplets is ≥1 nm, for example, it can be a nanoparticle size of 1 nm-100 nm, it can be a microparticle size of 0.1 um-100 um, etc. The inventors of the present application note that if the liquid-phase single-atom catalyst is used as a continuous phase, the reactants are introduced into the continuous phase in the form of bubbles for catalytic reaction, and the bubble size can be controlled in the range of 0.1 cm-1 cm, which is relatively large; however, existing solid catalysts can often achieve particles or micropores with a diameter of 10 nm-100 nm. In this embodiment, the catalytic efficiency is further improved by controlling the liquid-phase single-atom catalyst to perform interfacial contact catalysis with the reactants in the form of droplets. Compared with the continuous liquid phase (into which the reactants are bubbled), the droplets have a huge specific surface area, and the unit effective catalytic area is greatly improved. This embodiment is based on the combination of the high activity of the liquid-phase single-atom catalyst of the present invention and the droplet type with a high catalytic specific surface area, which further improves the catalytic activity and is conducive to large-scale industrial applications. The droplet-form liquid-phase single-atom catalyst combines the high activity, high efficiency, and high catalytic specific surface area of ​​single-atom catalysis. Its time with the reactants in the reaction system is controllable. In particular, when reacting with gaseous reactants in a fluidized bed, interfacial contact is sufficient, the catalytic reaction time is stable and controllable, and the product and catalyst can be effectively separated. Furthermore, in addition to the fixed-bed layout, after the reaction, the catalyst falls to the bottom of the reaction vessel in the form of droplets and / or cooled powder. By collecting the catalyst and separating it from impurities for reuse, the catalyst's service life is extended and production costs are reduced.

[0065] In addition, in the multiphase catalytic method for controlling interfacial contact in the form of droplets, any one of the following four methods can be used. 1) The liquid-phase single-atom catalyst can be introduced into the reaction vessel in the form of droplets by atomization, and the reactants are introduced into the reaction vessel, so that the reactants and the catalyst droplets are subjected to interfacial contact catalysis. Atomization methods include pressurization, dual-flow (air flow / liquid flow or liquid flow / liquid flow) atomization, ultrasound, centrifugation, etc. 2) The liquid-phase single-atom catalyst in the reaction vessel can be formed into droplets by heating, evaporation and recondensation, and the reactants are introduced into the reaction vessel, so that the reactants and the refluxed catalyst droplets are subjected to interfacial contact catalysis. 3) The material components that provide the chemical composition of the liquid-phase single-atom catalyst can be pre-loaded on the surface of a solid support (to obtain a carrier-loaded solid alloy catalyst) and introduced into a reactor. Under the reaction conditions, the material components on the surface of the solid support are heated and melted into droplets. The catalyst material component is loaded on the carrier at a low loading amount, and melts on the carrier after heating. Due to the low loading amount, the catalyst material component forms a droplet single-atom catalyst loaded on the solid carrier under the action of surface tension and / or carrier structure. Wherein, the loading amount can be determined according to the average particle size of the droplets. The specific steps are as follows: first, the metal source, carrier and solvent of the material component are mixed to obtain a suspension; secondly, the suspension is filtered and dried to obtain a precursor; then, the precursor is calcined and then reduced in a reducing gas atmosphere to obtain a carrier-loaded solid alloy catalyst; finally, the carrier-loaded solid alloy catalyst is directly sprayed into the reactor, or pre-filled in the reactor in a fixed bed manner, and then under the reaction conditions, the material component on the surface of the solid carrier can be heated and melted into droplets, that is, a liquid-phase single-atom catalyst, or further a droplet single-atom catalyst. 4) The liquid-phase single-atom catalyst or the material component that provides the chemical composition of the liquid-phase single-atom catalyst can be pre-prepared into an ultrafine powder, and the ultrafine powder is sprayed into the reactor and heated to form droplets under reaction conditions. Among them, the ultrafine powder can be prefabricated by a liquid phase single-atom catalyst using a method of rapid cooling after atomization, electron beam rapid cooling quenching, laser surface melting, mechanical crushing, etc. Mechanical crushing includes air flow milling, high-speed mechanical impact milling, vibration milling, stirring milling, ball milling, sand milling, cyclone milling, high-pressure roller (roller) milling, high-pressure water jet milling, high-pressure homogenization, ultrafine shearing and ultrasonic crushing.

[0066] In an optional embodiment, the step of forming droplets of the liquid-phase single-atom catalyst in the reaction vessel by heating, evaporation, and recondensation is performed by segmented temperature control, so that the liquid phase in the reaction vessel is evaporated, condensed, and atomized into droplets. The droplets are then suspended in the main reaction zone under the action of gravity and the rising hot air flow, and then undergo interfacial contact catalytic reaction with the introduced reactants in the form of droplets. The formation of droplets in the above-mentioned manner is simple to operate, convenient in temperature control, and more conducive to large-scale production. Specifically, the following steps may be included: Step 1) Dividing the reaction vessel into regions in the height direction, sequentially divided into a bottom high-temperature zone, a middle main reaction zone, and an upper cooling zone. Step 2) The liquid heterogeneous catalyst is pre-added to the bottom high-temperature zone of the catalytic reactor, and the low-boiling-point elements in the liquid heterogeneous catalyst are heated to become low-boiling-point element vapor; the low-boiling-point element vapor rises to the middle main reaction zone and the upper cooling transition zone of the preset catalytic reaction vessel, and then condenses and atomizes into droplets. Some droplets are suspended under the combined action of gravity and the rising hot air flow, and some droplets fall. The falling droplets are evaporated again into steam and rise in the bottom high-temperature zone to achieve circulation. During this cycle, the low-boiling-point element is continuously evaporated, condensed, and atomized to form catalyst droplets that reflux and suspend in the middle main reaction zone of the preset catalytic reaction vessel. Step 3) The gaseous reactant is introduced into the middle main reaction zone and fully contacts the reflux suspended droplets to cause a catalytic reaction. In addition, in the above embodiment, it is suitable for catalysis using a low-boiling-point liquid-phase single-atom catalyst with a normal pressure boiling point not higher than 1350°C. The liquid-phase single-atom catalyst is a low-boiling-point liquid-phase single-atom catalyst, and its chemical components include at least two selected from the group consisting of transition metal mercury, zinc, alkali metal lithium, sodium, potassium, rubidium, cesium, and alkaline earth metal magnesium. Furthermore, a low-boiling-point liquid-phase single-atom catalyst having a boiling point of no more than 1110°C at normal pressure is used for catalysis. The low-boiling-point liquid-phase single-atom catalyst, its material components include at least two selected from the group consisting of transition metal mercury, zinc, alkali metal sodium, potassium, rubidium, cesium, and alkaline earth metal magnesium. Furthermore, at least two selected from the group consisting of transition metal zinc, alkali metal sodium, potassium, and alkaline earth metal magnesium.

[0067] In an optional embodiment, the heterogeneous catalytic reaction may further include: inserting electrodes into the liquid-phase single-atom catalyst and conducting them. For example, liquid-phase single-atom LSACs are loaded into a container, and during the reaction, the electrodes are connected to the liquid LSACs and conducted, a voltage relative to the ground is applied to the LSACs, and catalysis is performed using an electrode pressure method, including positive and negative DC voltages, AC voltages, and pulse voltages. Under reaction conditions, the reactants are introduced into the container and fully contacted with the liquid LSACs. After the catalytic reaction occurs, the products and by-products are separated from the liquid LSACs. In this embodiment, the voltage applied to the electrodes can controllably change the adsorption and desorption of the reactants by changing the potential of the alloy melt, changing the pH, which is theoretically beneficial to enhancing the catalytic effect.

[0068] In an optional embodiment, the heterogeneous catalytic reaction may further include: treating the gaseous reactants to form a plasma. The plasma reactants fully contact the LSACs to generate a catalytic reaction, which can reduce the activation energy of the reactants and further improve the catalytic efficiency.

[0069] In an alternative embodiment, the heterogeneous catalytic reaction can also involve mixing solid catalyst particles with gaseous reactants and bubbling them into the continuous phase. The gaseous reactants react simultaneously with the liquid single-atom catalyst and the solid catalyst encapsulated in the gas bubbles. In other words, the heterogeneous catalytic reaction can also be performed using a solid catalyst and the liquid LSACs. The solid catalyst particles are mixed with the gaseous reactants and introduced into the reaction vessel together. The reactants fully contact the liquid LSACs to react, while simultaneously reacting with the solid catalyst particles within the gas bubbles. The undissolved or supersaturated precipitated products, unreacted materials, and byproducts float to the surface of the liquid along with the solid catalyst particles. Physical separation can then be employed.

[0070] In an optional embodiment, before performing heterogeneous catalysis, the method further includes: selecting a liquid-phase single-atom catalyst based on the absolute value of the Bader charge. Furthermore, selecting a liquid-phase single-atom catalyst based on the absolute value of the Bader charge means: determining the chemical composition of the liquid-phase single-atom catalyst based on the absolute value of the Bader charge, and determining the ratio of each element in the chemical composition based on the absolute value of the Bader charge. This embodiment selects a suitable catalyst based on the absolute value of the Bader charge before performing heterogeneous catalysis. By performing Bader charge calculations on catalysts under various formulations, such as multi-component molten alloys, the chemical composition is determined based on the calculated absolute value, and the ratio of each element in the chemical composition, i.e., the chemical composition, is determined, thereby selecting a liquid-phase single-atom catalyst with high catalytic activity.

[0071] The liquid-phase single-atom catalyst provided by the present invention can be widely used in nitration reactions, halogenation reactions, sulfonation reactions, amination reactions, addition reactions, elimination reactions, substitution reactions, including hydrogenation, dehydrogenation, oxidation, cracking, alkylation, isomerization reactions, etc. Specifically, it is used in any reaction process of dehydrogenation reaction, hydrogenation reaction, olefin hydroformylation reaction, ammonia-related reaction, petroleum refining catalytic reaction, biomass catalytic utilization, organic pollutant treatment and polymer material regeneration. For example, it includes but is not limited to: 1) methane thermal cracking, methane dry reforming, methane steam reforming, methane coupling to ethylene, methane oxygen-free coupling to aromatics, ethane dehydrogenation / oxidative dehydrogenation, propane dehydrogenation / oxidative dehydrogenation, C4 and above alkane dehydrogenation and oxidative dehydrogenation, ethylbenzene dehydrogenation, butane carbon dioxide coupling to light aromatics, dehydrogenation reactions such as aromatic hydrocarbons, polyolefins and asphalt thermal cracking reactions. 2) Hydrogenation reactions such as olefin hydrogenation or acetylene hydrogenation and olefin hydroformylation. 3) Ammonia-related reactions such as ammonia decomposition, ammonia synthesis, ammonia oxidation, aniline production from nitrobenzene, and SCR denitrification. 4) Catalytic reactions in petroleum refining. 5) Catalytic utilization of biomass, treatment of organic pollutants, and polymer material regeneration reactions.

[0072] In the above-mentioned embodiment, the provided liquid single-atom catalyst is in liquid state under the reaction conditions, directly performs interfacial contact catalysis with the reactants for heterogeneous catalytic reactions, can be prepared on a large scale, has good stability, is not easy to be deactivated and poisoned, has high catalytic activity and high catalytic efficiency. In particular, it can directly perform interfacial contact catalysis with the reactants without adding any solvent. The present invention realizes the reliable, environmentally friendly and economical large-scale preparation of highly active liquid-phase single-atom catalysts, which has the advantages of superior performance, stable quality, a wide variety, low cost, large output, high catalytic activity and efficiency, good stability, not easy to be deactivated and poisoned, combinable and adjustable active substances, controllable loading, simple and effective application method, wide range of applications, and low overall cost.

[0073] Compared with the prior art, the above embodiment of the present invention also has the following advantages:

[0074] 1. The present invention realizes the low-cost, large-scale, high-quality preparation of single-atom catalysts (SACs) using an economical method. Even if precious metals are used in this application, only trace amounts or even trace amounts need to be added, which greatly reduces the material cost. In order to reduce costs, the high-activity catalyst of the present invention uses a large amount of low-cost, easily available, green and safe elements. Cheap and resource-rich elements can be further used to replace the previous precious metals. For example, Mn, Fe, Ni, Bi, Ce, La, Cu, Zn, Al, Mg, S, etc. are used to replace Rh, Pt, Ru, Pd, Au, Ir, etc. Moreover, the preparation method mainly relies on simple processes such as heating and melting the elements in the formula according to the stoichiometric ratio. The method is simple and the quality is uniform and controllable. The microscopic mechanism given by nature in the liquid phase is used to achieve the uniform dispersion of natural "single atoms (including single ions)". The preparation cost is low and large-scale production can be carried out.

[0075] 2. LSACs exhibit high activity and efficiency in single-atom catalysis. This method is based on a profound microscopic mechanism of liquid physics: some elements are in quasi-ionic and associated single-atom states; clusters dissociate, elements are ionized and atomized, and then recombine. These elements are in single-ionic and associated single-atom states in the liquid and, together with the corresponding molecular ion clusters, become catalytic active centers. Therefore, the single-atom dispersion of LSACs catalysts is natural and dynamically stable, and the single-atom catalytic properties are well maintained during the reaction, without sintering or agglomeration issues. In addition to the atomic utilization efficiency, high selectivity, and high reaction kinetics of single-atom catalysis, they combine the uniform and single active centers of homogeneous catalysts with the stable and easily separable structures of heterogeneous catalysts, and also possess characteristics such as quantum size effects, unsaturated coordination environments, and strong active center-support interactions. The ultra-high catalytic performance per unit catalytic area confirms that LSACs possess the properties of single-atom catalysis. The components of the liquid-phase single-atom catalyst of the present invention also have co-catalytic interactions, and many elements that are generally considered inert also have strong catalytic activity, which greatly expands the selection range of existing catalysts. In many cases, the use of precious metals and toxic metals can be avoided. At the same time, the combination of many low-cost elements also achieves high catalytic efficiency.

[0076] 3. LSACs are highly stable and resistant to deactivation and poisoning. For solid-state active catalysts, products inevitably coat and accumulate on the surface during the catalytic process, leading to the inevitable deactivation and poisoning of highly active catalysts. In particular, carbon coating and surface oxidation are rapid and widespread. Unlike solid catalysts, which rapidly deactivate due to factors such as carbon deposition (coking), the liquid-phase single-atom catalysts of the present application provide a continuously updated gas-liquid interface and an environment for the continuous separation of products and byproducts (such as solid carbon), allowing the raw materials to fully contact new catalytic surfaces during the reaction. In particular, in LSACs, byproducts generally do not coat individual active sites, thus preventing deactivation. Selected alloy melts are highly resistant to common toxic impurities such as carbon monoxide and sulfur. Furthermore, if the melt is over-oxidized or reduced, it is easy to introduce an opposing gas for activation, eliminating the need for separate regeneration and activation outside the system. Due to these advantages, we only need to focus on selecting catalytic systems based on high activity, without excessive concerns about issues such as carbon deposition deactivation, oxidation deactivation, and impurity poisoning. The stability of liquid-phase single-atom LSACs includes resistance to poisoning and inactivation, and they can maintain reaction activity for a long time. Their stability is achieved by preventing the irreversible accumulation of products and by-products at the contact interface between the reactants and LSACs, including the undissolved / supersaturated precipitates of products and by-products that float to the liquid surface or sink to the bottom of the container.

[0077] 4. The present invention can have extremely wide applications. As a platform-type technical method and a huge range of formula combinations, the present invention can be widely used in methane thermal cracking, methane dry reforming, methane steam reforming, methane coupling to ethylene, methane oxygen-free coupling to aromatics, ethane dehydrogenation / oxidative dehydrogenation, propane dehydrogenation / oxidative dehydrogenation, C4 and above alkane dehydrogenation and oxidative dehydrogenation, ethylbenzene dehydrogenation, olefin hydrogenation, acetylene hydrogenation, synthetic ammonia, ammonia decomposition, ammonia oxidation, SCR denitrification, petroleum catalytic reforming, FCC fluid catalytic cracking, biomass catalytic utilization, pollutant treatment and polymer material regeneration, etc.; in particular, it provides large-scale engineering emission reduction and carbon reduction, and uses carbon dioxide to produce materials, chemicals and energy. The application of the present invention in the above-mentioned fields has high efficiency, low cost, simple process and good stability.

[0078] 5. The process conditions of LSACs are mild and controllable, and the separation is simple and efficient. When the liquid-phase single-atom catalyst uses a low-melting-point, high-density metal as the matrix, the entire system can operate at low and medium temperatures. There is also a wide range of selectivity to match the process. For strongly endothermic or exothermic reactions, the high thermal conductivity of the alloy melt and the much higher heat capacity than the gas phase, as well as the segmented temperature control of the reaction tower, allow the temperature to be controlled within a range that is favorable for the positive reaction and is also beneficial for heat recovery. During application, the reaction gas only needs to meet the reaction conditions and overcome the gravity of the metal to have a large space velocity, while conventional supported catalysts need to provide a large power consumption to overcome gas resistance. The products and by-products in the low-melting-point, high-density alloy melt are generally insoluble or difficult to dissolve in the melt, and can be effectively separated. The products and by-products will float directly or with bubbles, which is conducive to simple separation and continuous operation of the system, and is more conducive to large-scale preparation.

[0079] 6. LSACs can be combined in multiple ways. Conventional single-atom catalysts can only have a single element at their active sites, but the present invention allows multiple elements to synergize to achieve the effects of "multiple" single-atom catalysis. For example, as mentioned in the above embodiments, at least two second elements can be combined on their own, or a combination comprising a first element and a second element can be used. In a more preferred embodiment, at least two first elements and a second element can be combined.

[0080] 7. The present invention is reliable and environmentally friendly in the entire process chain of catalyst processing, use, recovery and heterogeneous catalytic reaction.

[0081] The liquid-phase single-atom catalyst, catalytic method and application thereof of the present invention will be further described below with reference to specific embodiments:

[0082] Example 1

[0083] The formula of manganese-based LSACs catalyst alloy is as follows:

[0084] Mn series A1: Bi, 0.01%Mn-99.99%Bi, 10Mn-90Bi (i.e., 10%Mn-90%Bi, at% is the atomic fraction, and this convention shall apply unless otherwise specified), 15Mn-85Bi, 18Mn-82Bi, 30Mn-70Bi;

[0085] Mn series A2: Sn, 5Mn-95Sn, 10Mn-90Sn, 18Mn-82Sn;

[0086] Mn series A3: 16.1Mn-83.9Ce, 25Mn-75Ce.

[0087] It should be noted that, unless otherwise noted, each catalyst system contains a comparative element (e.g., Bi and Sn in this example). The difference in catalytic efficiency between these elements and the alloy serves as a substantial comparison, and also constitutes a performance comparison between LSACs and non-LSACs. Graphite crucibles were used for the smelting and reaction of Ce-containing alloys, the same applies below. Furthermore, the alloy catalysts corresponding to the alloy formulations mentioned in this invention are all single-atom catalysts, exhibiting single-atom catalytic properties.

[0088] The catalytic device used in the catalytic reaction experiments of the present invention primarily comprises a reactor, a heating device for heating the reactor, a detection device connected to the reactor, and a reactant introduction device. Other supporting devices may also be included, such as an auxiliary heating device, a temperature detection device such as a multi-point thermocouple, and thermal insulation devices such as insulating quartz beads and quartz sand.

[0089] like Figure 1 As shown, in this embodiment, the heating device is a vertical tube furnace, and the reaction vessel is composed of a stainless steel outer sleeve + a quartz crucible. The stainless steel outer sleeve prevents the safety hazard caused by the breakage of quartz at high temperature and the leakage of alloy. The quartz crucible serves as the main reactor, which can eliminate the interference of the metal container in the catalysis. The detection device includes an online mass spectrometer and an online gas chromatography detection instrument. The reactant introduction device includes a quartz gas guide tube, which extends into the main reactor (the specific extension length is determined according to the length of the bubble column during the reaction). The reactant gas is introduced into the main reactor through the quartz gas guide tube to react with the catalyst in the main reactor. Specifically, as Figure 1 As shown, a quartz gas guide tube is inserted into the quartz crucible (reaction vessel), an online mass spectrometer (MS) and an online gas chromatograph (GC) are connected to the reaction vessel, and a K-type thermocouple is inserted into the melt. Before the catalytic experiment begins, the alloy is melted and the melt is cooled to the reaction temperature. A gas mass flowmeter (MFC) is used to introduce the mixed gas from above into the reaction vessel through a thin quartz tube, below the catalyst liquid level, via a pipeline. The online mass spectrometer (MS) and gas chromatograph (GC) perform analysis. K-type thermocouples measure the melt temperature in real time at multiple points during heating, holding, and bubbling reactions.

[0090] In this embodiment, a quartz crucible is used as the main reactor. The inertness of quartz does not react with the Mn-based alloy catalyst selected in this embodiment. Unless otherwise specified, the main reactor is a quartz crucible with a reactor diameter ID = 15 mm.

[0091] Reactions were conducted in bubble columns with total lengths of 150, 300, and 900 mm, respectively. The length of the bubble column was measured from the gas bubbling point at the bottom of the crucible to the top of the heated constant temperature zone. When melting the alloy, the components were loaded into the crucible according to the recipe and bubble column length. The temperature was then raised in stages to 1050°C, held for 12 hours while maintaining an Ar purge, and then reduced with hydrogen to produce the LSACs catalyst melt. Furthermore, multiple reactions can be performed simultaneously. For example, multiple reactors can be mounted on a stand, allowing catalytic experiments with 1-10 different catalyst formulations to be conducted simultaneously. The stand is placed in a vertical tubular furnace with multi-stage controlled heating, and the stand's bottom is supported and insulated by ceramic insulation. Thermal insulation at the upper and lower ends of the constant-temperature heating zone in the tubular furnace heating zone is provided by multiple layers of thermal insulation materials such as mica boards and asbestos on the top of the reaction crucible, and ceramic thermal insulation material at the bottom of the crucible; the 30mm alloy melt outside the heating zone intersecting the thermal insulation layer serves to reduce the pure thermal reaction in the headspace; the crucible outside the thermal insulation layer is exposed to the air and is cooled in the air by an external fan to keep it cool; the reactor headspace effect above the melt surface is further corrected using the reaction data of selected inert metals.

[0092] In this example, we carried out the following heterogeneous catalytic reactions to evaluate the catalyst performance: 1) EDH ethane dehydrogenation to ethylene; 2) OEDH ethane oxidative dehydrogenation to ethylene; 3) PDH propane dehydrogenation to propylene; 4) OPDH propane oxidative dehydrogenation to propylene; 5) BDH isobutane dehydrogenation to isobutylene; 6) DRM methane carbon dioxide dry reforming to synthesis gas; 7) MP methane thermal cracking to hydrogen; 8) AD ammonia decomposition; 9) SCR-NH3 denitrification.

[0093] 1) Ethane dehydrogenation to ethylene (EDH)

[0094] The reaction pressure was set at 0.1 MPa. After purging and pretreatment, 30 sccm of the reaction raw materials (feed ratio 25% C2H6, 75% Ar) were introduced into the above experimental apparatus. The catalytic performance of the above catalysts at reaction temperatures of 550°C, 700°C, 725°C, 750°C, and 775°C was investigated in bubble columns of 150 and 300 mm, respectively, including ethane conversion, ethylene selectivity, and ethylene yield (including headspace).

[0095] Ventilation tube orifice diameter ID = 2mm, single bubble diameter ~1cm, melt 150mm residence time ~1s, gas volume 0.5ml, catalytic area between bubble and alloy melt 3cm 2 The results are shown in the following table:

[0096] Table 1 Data of manganese series A1 (Mn-Bi) at 550°C, 700°C, 725°C, 750°C, and 775°C in a 150mm bubble column:

[0097]

[0098]

[0099] Table 2 Data of manganese series A1 (Mn-Bi) at 750°C in a 300mm bubble column:

[0100]

[0101] The catalytic performance of the 18Mn-82Bi catalyst was reduced by 0.4% when it was continuously operated at 750°C for 240 hours.

[0102] Comparative Example 1:

[0103] EDH was performed using commercial supported catalysts, and the results were:

[0104] (1) The initial conversion of ethane dehydrogenation over the Pt / SiO2 catalyst at 750°C was 27%, which dropped to 15% after 1 h and was completely deactivated after 5 h.

[0105] (2) The initial conversion of the Pt / Mg(Al)O catalyst was 19% and the selectivity was 99%, but it was almost completely deactivated after 40 min.

[0106] (3) The initial conversion rate of the PtSn / Mg(Al)O catalyst (Sn / Pt=1.08, Mg / Al=5) at 750°C was 24%, which dropped to 8% after 20 minutes and then to 5%, and was completely deactivated after 24 hours.

[0107] In the embodiment of the present application, the 18Mn-82Bi catalyst was continuously operated at 750°C for 240 hours, and the catalytic performance decreased by less than 1%.

[0108] It can be seen that the 18Mn-82Bi catalyst of this embodiment has superior stability compared with the comparative example 1.

[0109] Table 3 Data of manganese series A2 (Mn-Sn) at 700°C, 750°C, and 775°C in a 150mm bubble column:

[0110]

[0111]

[0112] Table 4 Data of manganese series A3 (Mn-Ce) at 700℃, 750℃, and 850℃:

[0113]

[0114] Furthermore, in other manganese-based reactions, La, Sm, Pr, and Nd exhibited excellent catalytic performance, surpassing Sn but falling short of Mn-Ce. Sn exhibited the worst catalytic performance among all manganese-based catalysts, and we used this as the headspace value. The actual catalytic performance is undoubtedly higher than the experimentally calculated value using this method. However, due to the excellent data, no further corrections were made.

[0115] Summarize the best values ​​of EDH data:

[0116] 30Mn-70Bi, 750℃, 150mm, minus Sn headspace ethane conversion rate is 37.5%, selectivity is 89.6%, and ethylene yield is 33.6%.

[0117] 15Mn-85Bi, 750℃, 300mm, minus Sn headspace ethane conversion 30.12%, selectivity 90.4%, ethylene yield 27.2%.

[0118] This indicates that the yield of 15Mn-85Bi at 300mm has reached that of 30Mn-70Bi at 150mm. Since the calculation after subtracting Sn actually overestimates the headspace, it can be considered that the optimal value under this condition is greater than this value.

[0119] As previously explained, non-precious metal catalysts are generally not used in dehydrogenation reactions prone to severe carbon deposition, such as EDH, due to their tendency to easily deposit carbon, low catalytic activity, and difficulty in activation and regeneration with oxygen, water vapor, or other methods (prone to overoxidation). This example not only demonstrates the high activity of single-atom catalytic LSACs in a Mn-based alloy melt, but also, because carbon continuously surfaces during the reaction, the interior of the melt remains clean, with virtually no decrease in catalytic activity. This stands in stark contrast to existing precious metal catalysts, which require constant activation and regeneration.

[0120] 2) OEDH Ethane Oxidative Dehydrogenation to Ethylene: Weak Oxidative Dehydrogenation of Ethane with CO2 to Ethylene: The reaction pressure was set at 0.1 MPa. After purging and preconditioning, the above experimental apparatus was introduced with 20 sccm of the reaction feed (feed ratio: 18% C2H6, 23% CO2, 59% Ar). The catalytic performance of each catalyst at 700°C was evaluated in a 150 mm bubble column, including ethane conversion, ethylene selectivity, and ethylene yield (including headspace). The results are as follows:

[0121] Table 5 Catalytic data of manganese system in weak oxidative dehydrogenation of ethane to ethylene

[0122]

[0123] Comparing Table 5 with Table 1, it can be found that the effect of OEDH is better than that of EDH, and this reaction uses carbon dioxide as a raw material, which helps to reduce emissions.

[0124] In addition, the inventors of this application have further optimized the catalytic reaction of ethane oxidative dehydrogenation to ethylene by OEDH in the above embodiment 1 (2), and improved the bubbling method to a droplet method. Specifically, assuming that the average droplet diameter is 20 μm, the product / volume catalytic efficiency can reach 4.10 5 ml ethylene / ml catalyst·h, product / mass catalytic efficiency 4·10 4 ml ethylene / g catalyst·h.

[0125] Furthermore, for each embodiment of the present invention, according to conventional methods that can be used by those skilled in the art, the average diameter of the catalyst droplets can be reduced to the order of 0.1-10 μm, which can further improve the efficiency by 10% compared with the bubbling method. 3 -10 9 times the efficiency.

[0126] The catalytic efficiency per unit catalytic area was calculated based on 15Mn-85Bi (reaction temperature 700°C) in Table 5: bubble diameter 1 cm, residence time 1 s, catalytic area time 3 cm 2 ·s, the volume of the heated raw material is increased by 3.5 times, the volume of the reaction process is slightly increased, set to 4 times, and the efficiency per unit catalytic area is 1.2ml ethylene / cm 2 catalyst·h. In large-scale production, assuming a 25% bubble occupancy in the melt, the product / volume catalytic efficiency is 7.2 ml ethylene / ml catalyst·h, a catalyst density of 9, and a product / mass catalytic efficiency of 0.8 ml ethylene / g catalyst·h. When the vent hole diameter is 2 μm and the bubbles are reduced to 1 mm, the product volume catalytic efficiency is 72 ml ethylene / ml catalyst·h, and the product mass catalytic efficiency is 8 ml ethylene / g catalyst·h.

[0127] Comparative Example 2:

[0128] Xiaoyan Wang, Yuxin Wang, Brandon Robinson, Qiang Wang, Jianli Hu, Ethaneoxidative dehydrogenation by CO2 over stable CsRu / CeO2 catalyst, Journal of Catalysis: Volume 413, September 2022, Pages 138-149. OEDH: CO2: ethane: N2 = 3:4:1, GHSV = 4800 h -1At a reaction temperature of 700°C, the ethane conversion rate was 37% and the light olefin yield was 35%. The catalyst was 4 wt% Ru, CsRu / CeO2, CeO2 was a nanopowder with a particle size of <25 nm (BET), and the catalyst life was 3 months. Comparative Example 2: Catalytic efficiency per unit catalytic area: feed volume space velocity 2400 h -1 When the product / volume catalytic efficiency is 840ml ethylene / ml catalyst·h; the product / mass catalytic efficiency is ~105ml ethylene / g catalyst·h; the carrier particle size is 25nm, the bulk density is 0.6, and the true density is ~8g / ml. (The volume of the heated raw material is increased by 3.5 times, and the volume increases slightly during the reaction process has no effect on the calculation.) 1ml catalyst provides 3·10 7 cm 2 Catalytic area, the catalytic efficiency per unit catalytic area is 2.8·10 -5 ml ethylene / cm 2 Catalyst·h.

[0129] Comparison of catalytic efficiency per unit catalytic area: The catalytic efficiency per unit catalytic area of ​​the OEDH ethane oxidative dehydrogenation to ethylene in this embodiment is extremely high. Under the same conditions, the liquid phase single atom catalyst LSACs (15Mn-85Bi) is 10 times higher than that of the precious metal supported catalyst (CsRu / CeO2) in the comparative example 2. 5 times, that is, five orders of magnitude higher.

[0130] Cost Comparison (Cost): In this example, the primary cost of the OEDH ethane oxidative dehydrogenation to ethylene process is the Bi / Mn metal raw material price, which is less than 0.05 / g, a fraction of a few hundredths or even a few thousandths of that of precious metal dehydrogenation catalysts. The total melt preparation cost is approximately 0.05 / g. With a 2 μm pore diameter, a product / cost catalytic efficiency of 160 ml of ethylene / catalyst hour, and an annual catalyst replacement rate of no more than 2% (and a 10% annual depreciation factor), and 300 days of annual production, 72 g of olefins are produced per gram of catalyst per year, equivalent to 14.4 kg of olefins produced per catalyst cost. In Comparative Example 2, the product / mass catalytic efficiency is approximately 105 ml of ethylene / gram of catalyst hour; with 300 days of annual production, a catalyst life of three months, and four replacements, 189 L of ethylene is produced per gram of catalyst per year. Based on a catalyst preparation cost of 6 yuan / g, a precious metal recovery and regeneration factor of 0.5, and an annual maintenance cost of 12 yuan / g, the resulting yield is approximately 79 g of ethylene per catalyst hour. This embodiment is 180 times better than the comparative example 2.

[0131] 3) PDH Propane Dehydrogenation to Propylene: Manganese Series A1: The reaction pressure was set at 0.1 MPa. After purging and pretreatment, the above experimental apparatus was introduced with 30 sccm of the reaction feed (feed ratio 25% C2H6, 75% Ar). The catalytic performance of each catalyst at reaction temperatures of 675°C and 700°C was investigated in a 150 mm bubble column, including propane conversion, olefin yield, ethylene selectivity, and propylene selectivity (including headspace).

[0132] Table 6 Catalytic data of manganese system A1 in PDH propane dehydrogenation to propylene

[0133]

[0134] It can be seen from Table 6 above that 15Mn-5Cu-80Bi performs better. Since the catalytic effect of Sn is not equal to the headspace, the optimal reaction temperature should be 700°C.

[0135] Large-scale preparation and application (18Mn-82Bi): A single bubble column reactor was expanded, loaded with an 18Mn-82Bi alloy catalyst, and heated and melted using a primary heat source. The feed gas, containing 90% propane, was preheated in a secondary heat source preheater before entering the reactor through a SiC porous ceramic aeration plate at the bottom of the bubble column. The reaction temperature was 605-705°C, and the inlet pressure of the reaction gas was atmospheric pressure + ρgh + a small amount of air resistance, where ρ is the density of the alloy melt, g is the acceleration due to gravity, and h is the height of the liquid alloy in the bubble column. The olefin yield was 22%. The post-reaction gas was continuously separated by a cyclone to remove entrained carbon deposits. The 18Mn-82Bi catalyst operated continuously at 700°C for 240 hours with a catalytic performance drop of less than 0.3%.

[0136] Comparative Example 3:

[0137] (1) The UOP process for propane dehydrogenation uses <1 wt% Pt and 1-2 wt% Sn loaded on Al2O3, with <1 wt% Na or K as additives. The catalyst is kept in a flowing state during production and is regenerated in the final regeneration unit (CCR). During regeneration, a chlorine-oxygen mixture is introduced to remove carbon deposits and redisperse the Pt. The regenerated catalyst is then returned to the first reactor to ensure continuous dehydrogenation. Because Pt clusters inevitably aggregate and grow during the sintering process, the catalyst must be completely replaced after four years.

[0138] (2) PetroChina CN202110677830.8 patent method, pseudo-boehmite powder and 5% dilute nitric acid are uniformly mixed, and a spherical alumina carrier is prepared by a rolling ball molding method. The average diameter of the carrier is 1.65 mm, and a Pt / Zn / Al2O3 catalyst is prepared by an impregnation method. The catalyst is loaded into a fixed bed quartz reactor, and the reaction temperature is controlled to 600 ° C, the reaction pressure is 0.1 MPa, the molar ratio of propane: hydrogen is 1:0.5, the reaction time is 24 h, and the propane mass space velocity is 3 h 1 The catalytic efficiency decreased by 3.5% after 24 hours of catalysis.

[0139] The catalyst preparation method comprises mixing 100 g of P-DF-03-LS pseudo-boehmite powder (produced by Shandong Aluminum Co., Ltd.), 50 g of SB imported German pseudo-boehmite powder (purchased from Beijing Asia Pacific Aohua Chemical Additives Co., Ltd.), 85 g of 5% dilute nitric acid, and 5 g of sesbania powder. The mixture is then transferred to a kneader and stirred until uniformly mixed. The kneading temperature is 35°C, the kneader spindle speed is 150 rpm, and the kneading time is 1 hour.

[0140] Put the evenly mixed raw materials into the hopper of the micro pelletizer, select an extrusion die with a pore size of 1.8 mm, adjust the extrusion speed to 2 m / min, and the cutting speed to 1200 pellets / min, extrude the raw materials into strips and cut them into small round pellets.

[0141] The above-mentioned small round particles were placed in a micro-pellet shaping machine for shaping. The shaping conditions were as follows: the spheronization time was 3 minutes / time, the spheronization times were 3 times, and the sample chamber speed was 300 r / min.

[0142] The standard spherical raw material balls obtained after shaping were placed in a pellet screening machine to screen out spherical precursors with a size of 1.7 mm. The spherical precursors were dried at 110°C for 8 hours and then calcined at 600°C for 15 hours to obtain spherical alumina supports.

[0143] 0.080g of H2PtCl6·6H2O and 0.321g of Zn(NO3)2·6H2O were dissolved in 100mL of deionized water in a round-bottom flask to obtain a mixed solution. 10g of the spherical alumina support obtained in the above step was added to the mixed solution for impregnation. After continuous stirring in a 50°C water bath for 8 hours, the solvent water in the system was evaporated using a rotary evaporator to obtain a solid product. The solid product was placed in a drying oven at 110°C for 6 hours and then calcined in a muffle furnace at 550°C for 8 hours to obtain a dehydrogenation catalyst. Based on the total weight of the dehydrogenation catalyst, the platinum component content (calculated as platinum element) was 0.3% (weight percentage), and the zinc component content (calculated as zinc element) was 0.7% (weight percentage).

[0144] (3) Barias OA, Holmen A, Blekkan EA, Propane dehydrogenation oversupported Pt and Pt-Sn catalysts: catalyst preparation, characterization, and activity measurements[J]. Journal of Catalysis, 1996, 158(1): 1-12. It was found that at 427℃, the activity of Pt / Al2O3 catalyst decreased rapidly.

[0145] Comparison of catalytic efficiency between the embodiment and the comparative example: The yield of the large-scale preparation is 22%. According to the vent hole diameter of 2 μm and the bubble size of 1 mm, the product / volume catalytic efficiency is 124 ml olefin (ethylene + propylene) / ml catalyst·h, and the product / mass catalytic efficiency is 13.8 ml olefin / g catalyst·h = olefin catalytic efficiency 0.0258 h -1 Comparative Example 3 (2) conversion rate according to the current higher 35%, propylene / mass catalytic efficiency 0.7h -1 .

[0146] Stability comparison between the example and the comparative example: The large-scale preparation of the example shows high catalytic efficiency, a long catalyst life, and a low rate of activity and catalytic efficiency decline. The liquid-phase single-atom catalyst of the present application has excellent stability. As mentioned above, the 18Mn-82Bi catalyst operated continuously at 700°C for 240 hours with a catalytic performance drop of less than 0.3%. Conventional supported catalysts, such as Pt / Sn / Al2O3, Pt / Zn / Al2O3, and Pt / Al2O3, have the following problems: the catalyst needs to be completely replaced after a few years; the catalytic efficiency drops significantly after 20 hours of catalysis, for example, by 3.5%; and the catalyst activity drops rapidly after 400-500°C, leading to deactivation.

[0147] Cost comparison between the Example and the Comparative Example: The primary costs of this Example are the Bi / Mn metal raw material price, less than 0.05 / g, plus the total melt preparation cost of ~0.05 / g. The annual catalyst replacement rate does not exceed 2%, and annual depreciation, etc., is calculated at 10%. With 300 days of production per year, the cost per catalyst unit can produce 37.1 kg of olefins. This is approximately 1 / 100 of the cost of the supported Pt / Zn / Al2O3 catalyst in Comparative Example 3.

[0148] Comparison of reaction conditions between the Example and the Comparative Example: The supported catalyst, with its microporous structure, limits the ingress and egress of the reactant gases to diffusion, resulting in a low reaction rate. Catalyst loss and periodic replacement complicate the recovery system. In this example, local heat and mass transfer occur at the bubble / melt interface. Within the reaction pressure and reaction time, the mass transfer and transport limitations of two-phase surface reactions can be safely ignored, and the transport limitations are determined solely by the gas-liquid surface area, resulting in a high reaction rate. The catalyst can be replenished in small quantities over long periods of time without requiring replacement.

[0149] Comparative Example 4:

[0150] UOP's Oleflex process uses a Pt-Sn / Al2O3 catalyst and a moving bed reactor. The reaction temperature is between 525 and 705°C, and the reaction pressure is 1 to 3 bar. It generally consists of four adiabatic reactors, which are connected by preheaters. The gas passing through the preheaters is the main heat source for the reactor system. The catalyst is in a flowing state during the production process and is regenerated in the final regeneration unit (CCR). During regeneration, a chlorine-oxygen mixture is introduced to remove carbon deposits and redisperse the Pt. The regenerated catalyst then flows back into the first reactor to ensure the continuous dehydrogenation reaction.

[0151] Comparison of devices and processes: In comparative example 4, the loaded catalyst process requires multiple reactors, and the main reactor cannot be heated, and the temperature gradient is unreasonable. In particular, the reactor and catalyst regeneration are actually a composite system. The complex moving bed reaction process technology and the complex kinetic control of carbon deposit burning and regeneration require control of oxygen, water vapor, carbon dioxide, methane and other side reaction products, as well as complex temperature distribution control. An independent CCR treatment device is also required, which constitutes the majority of the investment. Moreover, in the moving bed, the reactant flow crosses the catalyst bed composed of millimeter-sized catalyst particles, which brings instability. At the same time, gas resistance causes the radial crossing distance of the gas to be small, and the catalytic contact is insufficient. The reaction pressure of the required serial reactors is relatively high. A large amount of unconverted propane needs to be recycled.

[0152] The large-scale preparation of the present invention adopts a single bubble column reactor, which does not require interstage heating and the temperature setting is consistent with the optimal process conditions; the catalyst does not need to be regenerated, and there is no catalyst regeneration system; it only needs to remove the carbon deposits that naturally float to the liquid surface, and there is no need for complex moving bed reaction process technology; the gas resistance is small, the energy consumption is low, and the process is simple, stable, and low-consumption.

[0153] 4) OPDH propane oxidative dehydrogenation to propylene:

[0154] Manganese series A1: Mn-Bi

[0155] Propane Weak Oxidative Dehydrogenation to Propylene: The reaction pressure was set at 0.1 MPa. After purging and preconditioning, the experimental apparatus described above was fed with 20 sccm of the feedstock (feed ratio: 21% C₂H₂, 22% CO₂, 57% Ar). The catalytic performance of each catalyst at 650°C was evaluated in a 150 mm bubble column, including propane conversion, olefin yield, and propylene and ethylene selectivity (including headspace). The results are as follows:

[0156] Table 7 Catalytic data of manganese system in weak oxidative dehydrogenation of propane to propylene

[0157]

[0158] 5) BDH isobutane dehydrogenation to isobutylene:

[0159] 20Mn-80Bi: The reaction pressure was set at 0.1 MPa. After purging and pretreatment, 5 sccm of isobutane and 3 sccm of CO2 were introduced into the experimental apparatus. The catalytic performance of the catalyst 20Mn-80Bi at a reaction temperature of 600°C was examined in a 150 mm bubble column, yielding an isobutane yield of 37%.

[0160] 6) DRM methane and carbon dioxide dry reforming to produce synthesis gas:

[0161] The reaction pressure was set at 0.1 MPa. After purging and preconditioning, the experimental apparatus was introduced with 30 sccm of the reaction feedstock (feed ratio: 47% CH₄, 23% CO₂, 30% Ar). The catalytic performance of each catalyst at a reaction temperature of 1000°C was evaluated in 150 mm and 600 mm bubble columns, including methane and carbon dioxide conversions, and hydrogen and carbon monoxide yields (headspace excluded). The results are shown in Table 8 below:

[0162] Table 8 Catalytic data of manganese system in dry reforming of methane and carbon dioxide to produce synthesis gas

[0163]

[0164] 7) MP methane thermal cracking to produce hydrogen:

[0165] The reaction pressure was set at 0.1 MPa. After purging and preconditioning, the experimental apparatus was fed with 10 sccm of the reaction feedstock (feed ratio: 50% CH₄, 50% Ar). The catalytic performance of each catalyst at a reaction temperature of 1040°C was examined in a 150 mm bubble column, including methane conversion and hydrogen-to-carbon yield (headspace excluded). The results are as follows:

[0166] Table 9 Catalytic data of manganese in methane thermal cracking to produce hydrogen

[0167] Depth (mm) Metal and alloy formulations <![CDATA[CH4 conversion rate %]]> <![CDATA[H2 production rate %]]> 150 10Mn-90Bi 5.39 5.36 150 30Mn-70Bi 33.80 32.83 150 27Ni-73Bi comparison 22.19 22.07 150 50Mn-50Bi comparison 30.75 29.84

[0168] Table 9 shows that the catalytic efficiency of the manganese-based 30Mn-70Bi catalyst is higher than that of the nickel-based 27Ni-73Bi catalyst. Furthermore, the catalytic efficiency of 30Mn-70Bi is higher than that of 50Mn-50Bi, which has an increased amount of active metal Mn. This indicates that reducing the traditional active metal Mn content and increasing the traditional inert metal Bi content in 50Mn-50Bi actually leads to increased catalytic activity, reflecting the co-catalytic nature of the various components of LSACs.

[0169] 8) AD ammonia decomposition:

[0170] The reaction pressure was set at 0.1 MPa. After purging and pretreatment, the experimental apparatus was introduced with 10 sccm of a mixture of NH3 (feed ratio: 32% NH3, 68% Ar). The catalytic performance of each catalyst at a reaction temperature of 950°C was examined in a 160 mm bubble column. The conversion rates were as follows:

[0171] Table 10 Catalytic data of manganese system in ammonia decomposition

[0172] Temperature Metal and alloy formulations Ammonia decomposition conversion rate % 900 30Mn-70Bi 61.70 900 20Mn-5Cu-75Bi 66.19 900 25Mn-75Bi 55.62 900 18Mn-2Li-80Bi 67.55 900 Sn 1.70 950 30Mn-70Bi 92.09 950 20Mn-5Cu-75Bi 97.83 950 25Mn-75Bi 87.78 950 18Mn-2Li-80Bi 99.58 950 Sn 3.07

[0173] With other conditions remaining unchanged, 8000V plasma was used to assist in the activation of the raw gas, and the ammonia decomposition conversion rate of 18Mn-2Li-80Bi was 89.21% at 600°C.

[0174] As can be seen from Table 10, the catalytic efficiency of 18Mn-2Li-80Bi and 20Mn-5Cu-75Bi is higher than that of 25Mn-75Bi, indicating that the catalytic activity of the alloys of two active elements in the first element (Mn-Li and Mn-Cu) with Bi is better than that of the alloys of only one active element in the first element, Mn, with Bi. This combination of formulas can exert the synergistic catalytic effect of multiple active metal elements and improve the catalytic efficiency.

[0175] Table 11 Ammonia decomposition conversion of 18Mn-2Li-80Bi at 950℃

[0176] Temperature ℃ / bubble column height Metal and alloy formulations Ammonia decomposition conversion rate % 950 / 160 18Mn-2Li-80Bi 99.58 950 / 300 18Mn-2Li-80Bi 99.99

[0177] Large-scale preparation and pilot application experiments:

[0178] Catalyst formula: 30Mn-70Bi, pressure 0.1MPa, the experimental reactor was changed to a graphite crucible, the reactor diameter ID = 180mm, the raw gas NH3 was supplied from the bottom through a ceramic aeration plate (aeration plate diameter 150mm, micropore diameter ~10um), the gas flow rate was 12SLM, and the catalytic performance of each catalyst at reaction temperatures of 950℃, 850℃, and 750℃ was investigated in a 100mm bubble column. The conversion rates were 100%, 100% and 58% respectively within the error range.

[0179] Compared with the catalytic effect of the vent tube with an orifice diameter ID = 2 mm in Table 10 above, the catalytic efficiency is greatly improved, and the reaction temperature is further reduced, reflecting the rapid improvement of the catalytic efficiency after the catalytic area is increased.

[0180] Catalyst formula: 18Mn-82Bi / ZSM-5, manganese nitrate (Mn(NO3)2) and bismuth nitrate (Bi(NO3)3) are dispersed in a 2% dilute nitric acid solution at a Mn:Bi ratio of 30:70. The solution is ultrasonically vibrated for 30 minutes, and the above solution is added dropwise to 2 times the mass of molecular sieve ZSM-5 and stirred evenly for wet impregnation. The above sample is sealed and aged for 24 hours. It is then placed in an oven at 105°C for 24 hours, ground evenly with a mortar, and placed in a modified catalyst. The above catalyst is reduced with H2 in a 550°C tubular furnace for 5 hours, cooled, and ground again to obtain a Mn-Bi catalyst Mn supported on a molecular sieve. 0.3 Bi 0.7 / ZSM-5, stored in a sealed and dry place in a storage tank. The reaction was carried out in a quartz crucible with a total length of 1000mm, and the reaction zone was filled with 100mm quartz beads (OD = 30um), 400mm catalyst Mn 0.3 Bi 0.7 / ZSM-5, and 100mm quartz beads (OD=30μm). A mass flowmeter (MFC) was used to introduce the mixed raw gas from the bottom of the crucible. The length of the reaction zone matched the length of the constant-temperature heating zone, which was insulated by a tube furnace heating zone (600mm long) at the top and bottom, and by multiple layers of insulation, such as mica, ceramic, and asbestos, at the top and bottom of the crucible (150mm and 250mm long, respectively). Outside the insulation, the top and bottom of the crucible were exposed to air and kept cool by an external fan to minimize the effects of pure headspace reactions. Headspace effects were further corrected using reaction data from selected inert metals. A K-type thermocouple in the crucible measured the temperature in real time during the reaction. The reaction pressure was set at 0.1MPa and the reaction temperatures were 850 and 775°C. After purging the experimental apparatus, 600sccm of pure NH3 gas was introduced, resulting in an ammonia decomposition conversion of 100%. Compared with the catalytic effect of the aforementioned ID=2mm vent tube, the catalytic efficiency is greatly improved, and the reaction temperature is further reduced, reflecting the rapid improvement of the catalytic efficiency after the catalytic area of ​​the droplet catalyst is increased.

[0181] Comparative Example 5:

[0182] Ru / CNTs: X% Ru / CNTs(OH) were obtained using ethylene glycol liquid-phase reduction deposition. The optimized range for x% was 3-6%, with 4.2% being the preferred value. At 873 K and a GHSV of 30,000 mL / h·g, the ammonia decomposition conversion of 4.2% Ru / CNTs(OH) was 98%.

[0183] Cost Comparison: In Comparative Example 5, assuming a ruthenium price of 110 yuan / g, the material cost of the 4.2% ruthenium component of the catalyst is 4,600 yuan / kg, which, taking into account preparation costs, is 5,000 yuan / kg. In contrast, the material cost of all Mn-based alloys in this example is less than 50 yuan / kg, and considering melt preparation, the direct cost is less than one-hundredth of that of the Ru / CNTs catalyst.

[0184] 9) SCR-NH3 Denitrification: 5Mn-95Bi, 10Mn-1Ce-Bi, and 18Mn-58Bi-24Sn alloys were refined at a reaction pressure of 0.1 MPa. After purging and pretreatment, a 30 sccm mixture of the reaction raw materials (feed ratio: 2% NH3, 2% NO, 28% O2, 68% Ar) was introduced into the experimental apparatus. The catalytic performance of each catalyst at various reaction temperatures was examined in a 150 mm bubble column. The conversion rates are as follows:

[0185] Table 12 Catalytic data of manganese system in desulfurization

[0186] Temperature Metal and alloy formulations NO conversion rate % 330 Sn 0.97 330 5Mn-95Bi 36 480 Sn 14 480 5Mn-95Bi 59 480 10Mn-1Ce-Bi 71 480 18Mn-58Bi-24Sn 95 600 Sn 0 600 5Mn-95Bi 93 600 10Mn-1Ce-Bi 98.73 600 18Mn-58Bi-24Sn 99.97

[0187] Furthermore, Mn-based LSACs possess ammonia decomposition capability. No residual ammonia was detected in the 10Mn-1Ce-Bi and 18Mn-58Bi-24Sn formulations at 600°C. The catalytic efficiency remained unchanged after 100 hours of reaction. Adding 2% SO2 to the reaction gas mixture also resulted in minimal changes in catalytic efficiency. Furthermore, the 18Mn-58Bi-24Sn alloy exhibited no NO detection at 60 sccm of simulated coal flue gas at 480°C, with a 300mm bubble column.

[0188] Comparative Example 6:

[0189] A commercially available honeycomb catalyst with an active component (V2O5) and a carrier (WO3 / TiO2) was used. The flow area was about 80%, and the denitrification of coal-fired flue gas was simulated at 480°C. (1) High-temperature denitrification followed by low-temperature dust removal process. The denitrification catalyst has been in a high-concentration dust and flue gas working condition for a long time, and the catalyst wear, clogging, and poisoning are still serious, which shortens the catalyst life, reduces the denitrification efficiency, and increases the operating cost. The waste vanadium titanium catalyst is a hazardous waste and has a toxic effect on the environment and human body. The arrangement density is large and it is not easy to disassemble. (2) High-temperature electrostatic dust removal followed by low-temperature denitrification process. It has a certain effect on extending the life of the catalyst, but the dust removal effect still cannot achieve the effect of preventing wear, clogging, and poisoning. The dust removal and denitrification processes are still two independent devices, occupying a large area, with poor synergistic function and poor ultra-low emission stability. The pollution problem of waste vanadium titanium catalyst still exists.

[0190] Comparison of Denitration Applications: In Comparative Example 6, the high-temperature denitration followed by low-temperature dust removal inevitably exposes the denitration catalyst to high dust concentrations for extended periods. Furthermore, flue gas dust is a major cause of catalyst wear, clogging, and poisoning, shortening catalyst life, reducing denitration efficiency, and increasing operating costs. In contrast, the catalyst in this example maintains its long-term activity, demonstrating that the liquid, high-density alloy in the catalytic system can withstand high temperatures and high dust and ash content. Dust rapidly emerges from the melt, without affecting catalytic activity, and is resistant to the toxic effects of sulfur oxides. Therefore, it can be placed in the high-temperature section before dust removal. There is no ammonia residue or toxic metal contamination. Therefore, this catalytic system outperforms existing catalysts in SCR-NH3 denitration.

[0191] The following describes the large-scale preparation and application method of the catalyst of the present invention, and its large-scale promotion and implementation, taking the Mn-based LSACs catalyst of this embodiment as an example. The general steps are as follows:

[0192] Before the catalytic experiment begins, the alloy is melted. The Mn-alloy components are loaded into a bubble column reactor according to the recipe and ratio. The temperature is raised in stages to 800-1050°C, held for 4-12 hours, and maintained under an Ar purge. The LSACs catalyst melt is then reduced with hydrogen.

[0193] The operating temperature of the reactor reaches the preset reaction temperature.

[0194] Microporous aeration plates (pore diameter 1-100 μm) introduce the reaction gases from the bottom, collecting and separating the gaseous products and by-products at the top. Meanwhile, by-products and impurities that float to the surface of the melt are removed mechanically or by wind. LSACs have higher catalytic efficiency than conventional aeration tubes and maintain long-term stability without deactivation or poisoning, resulting in extremely low catalyst consumption during the reaction.

[0195] This shows that scaling up the experimental LSACs catalyst preparation method will not increase costs. On the contrary, industrial optimization can reduce costs and achieve more efficient catalysis.

[0196] For comparison:

[0197] The co-precipitation method for the preparation of solid-supported single-atom catalysts requires strict control of the temperature and rotation speed of the reaction system, the use of a buffer solution to regulate the pH of the system, the precipitation of metal salts onto the support by adding a suitable precipitant, and then the SAs catalyst is obtained after complex treatments such as washing, drying or calcination. In the earliest preparation of single-atom catalysts, Zhang Tao et al. mixed H2PtCl6 and Fe(NO3)3 aqueous solutions in a certain addition ratio, titrated the mixture into an alkaline solution under stirring conditions, and obtained a precipitate containing the target metal. The precipitate was filtered, washed, dried, and then calcined to finally obtain the Pt SACs catalyst Pt1 / FeO with FeOx as the support. x 0.17wt% Pt1 / FeO prepared by the above coprecipitation method x As a single atom catalyst, 2.5wt% Pt1 / FeO x The catalyst contains both single atoms and clusters. This indicates that solid-state supported single-atom catalysts can only be controlled on a small scale in the laboratory, which is extremely expensive and difficult to increase the loading capacity.

[0198] Generally speaking, when solid-state supported single-atom catalysts are prepared using wet chemical methods (coprecipitation, impregnation), the synthesis conditions can be precisely controlled under laboratory conditions, resulting in atomically dispersed noble metal catalysts. However, when scaling up production at the synthesis ratio, uneven mass and heat transfer effects often occur, which can easily lead to localized uneven concentrations and thus noble metal agglomeration. Other techniques, such as mass separation-soft landing and atomic layer deposition, are often limited by expensive experimental equipment and low yields, making industrial application difficult.

[0199] Furthermore, the stability of single-atom catalysts limits their further commercialization prospects. Commonly reported single-atom catalysts for oxygen reduction and oxygen evolution reactions often have a stability of 10 to 100 hours, whereas commercial electrolysis and fuel cell devices often require a stability of ~8000 hours.

[0200] Example 2

[0201] The catalytic reaction experimental device is the same as that in Example 1

[0202] LSACs catalyst alloy formula:

[0203] Ni series B1: 0.01%Ni-99.99%Bi, 3.6Ni-96.4Pb (i.e. 3.6%Ni-96.4%Pb, at%, unless otherwise specified), 13Ni-71Bi-16Sn, 3.9Ni-13Mn-67.5Bi-15.6Sn, 10Ni-20Mn-70Bi;

[0204] Ni series B2: 18Ni-72Ce, 20Ni-35Ce-45La, 20Ni-25Ce-30La-25Sm.

[0205] As above, before commencing the catalytic experiment, the alloy was melted. The loading of each component was measured according to the recipe and bubble column length, then placed in a crucible. The temperature was raised in stages to 1050°C and held for 12 hours while maintaining an Ar purge. The LSACs catalyst melt was then reduced with hydrogen to the reaction temperature. In this example, the following EDH heterogeneous catalytic reactions were performed to evaluate the catalyst performance:

[0206] Table 13 Catalytic data of nickel-based (including Ni-Bi) catalysts in EDH heterogeneous catalytic reaction

[0207]

[0208]

[0209] Table 14 Catalytic data of nickel-based (including Ni-Ce) catalysts in EDH heterogeneous catalytic reaction

[0210] Temperature Metal and alloy formulations Ethane conversion rate % Ethylene selectivity% 750 18Ni-72Ce 29.95 97.1 750 20Ni-35Ce-45La 39.47 96.8 750 20Ni-25Ce-30La-25Sm 40.02 98.0

[0211] It can be seen that the catalytic efficiency of 20Ni-25Ce-30La-25Sm is higher than that of 20Ni-35Ce-45La, indicating that the catalytic activity of the alloy of the three active elements (Ce, La, Sm) in the first element and Ni is better than that of the alloy of only two active elements (Ce, La) in the first element and Ni. The above formula combination can exert the synergistic catalytic effect of multiple active metal elements and improve the catalytic efficiency.

[0212] From Examples 1 and 2, it can be seen that traditionally only precious metals can be used for dehydrogenation. Studies have shown that solid non-precious metal Ni and Mn catalysts are very prone to carbon deposition, and the carbon produced by the reaction is deposited on and around the active sites of the catalyst. On the one hand, coking inhibits the adsorption of reactant molecules on the active sites, resulting in gradual deactivation and a decrease in conversion rate; on the other hand, carbon can fill pores or cover the surface of the catalyst, preventing the reaction gas from entering the active sites; on the other hand, the coverage of the catalyst reduces the heat transfer rate to the metal, thereby reducing the diffusion rate through the pores; on the other hand, hard carbon tubes may also be formed, leading to catalyst disintegration. The most commonly used regeneration methods are steam, air and carbon dioxide, but non-precious metal catalysts are difficult to regenerate and are prone to sintering of active centers, changes in catalyst morphology and structural disintegration. As mentioned above, LSACs do not accumulate carbon on the catalytic surface, and the catalytic mechanism of liquid-phase single atoms makes the catalytic activity exceed that of solid precious metal catalysts. Therefore, non-precious metals such as Mn, Ni, Fe, Co, Cu, Zn, Cr, Ti, Li, Na, K, Al, Ce, La, and Sm have become new choices for LSAC material components. They can be applied on an industrial scale to dehydrogenation reactions such as the dehydrogenation of C1-C3, C4 and above alkanes, the dehydrogenation of ethylbenzene, the coupling of butane with carbon dioxide to produce light aromatics, and the thermal cracking of aromatic hydrocarbons, polyolefins, and asphalt.

[0213] Example 3

[0214] The catalytic reaction experimental device is the same as that in Example 1

[0215] LSACs catalyst alloy formula:

[0216] Pt series C1: 0.01% Pt-99.99% Bi, 5Pt-95Pb (i.e., 5% Pt-95% Pb, at%, hereinafter referred to as such unless otherwise specified), 5Pt-95Ga, 5Pt-95Bi, 5Pt-95In, 5Pt-95Sn, 10Pt-90Pb, 10Pt-90Ga, 10Pt-90Bi;

[0217] As before, the alloy was melted before the catalytic experiment began. The components were loaded into a crucible according to the recipe and bubble column length. The temperature was raised in stages to 1050°C and held for 12 hours. Ar was maintained under a purge of hydrogen and the LSACs catalyst melt was reduced to the reaction temperature.

[0218] In this example, we performed the following EDH heterogeneous catalytic reactions to evaluate the catalyst performance:

[0219] Table 15 Catalytic data of Pt system in EDH heterogeneous catalytic reaction

[0220]

[0221]

[0222] Without being limited to this embodiment, the unit catalytic area efficiency of the bubbling method of the present invention and the existing solid supported catalyst fixed bed catalysis were calculated and compared.

[0223] Bubble method catalytic area: V1: cold reaction gas volume, d1 / r1 bubble diameter / radius, generally set d1 = 0.1 ~ 1cm, first take 1cm, Vc1: bubbling method catalyst volume, Mc1: bubbling method catalyst mass, catalyst density set 8-10 take 9, catalytic time t1 is temporarily set to 1s (15cm bubble column), then the catalytic rate (similar to the space velocity concept) c1 = V1 / Vc1 (when the catalytic area S1), in addition, the raw gas thermal expansion and reaction increase is m, set to 5, the industrial scale bubble to melt ratio, that is, the bubble ratio is 0.2-0.25, take 0.25. S1 = 4πr1 2 , V1=4πr1 3 / 3, c1=0.05 (when catalytic area S1=3cm 2 At this time, assuming the catalytic conversion rate is x1 and the selectivity is 100%, the catalytic volume efficiency is x1 / 20 (s -1 )=180x1(h -1 );

[0224] The total effective catalytic area of ​​the fixed bed solid supported catalyst is: s2: the area of ​​a single solid supported catalyst particle, S2' the area of ​​the fixed bed solid supported catalyst carrier, the loading rate is set to 3wt%, S2'~=0.03S1, V2: the volume of the hot reaction gas, d2 / r2 active catalyst particle diameter / radius, generally set d2=20nm, r2=10 -6 cm, Vc2: catalyst carrier volume, Mc2: catalyst carrier mass, catalyst carrier density is set to 4-6, take 5, raw gas thermal expansion and reaction increase to m. Space velocity s, assuming catalytic conversion rate x2, selectivity 100%, then the catalytic volume efficiency under approximate conditions is x2s (h -1 ); V2 / Vc2 is generally = 0.5, the reaction gas that Vc2 catalyst can catalyze per hour = smV2 / 3600Vc2 = sm / 7200 (ml, when the catalytic area is S2), let Vc2 = Vc1, that is, corresponding to the same catalyst volume (and catalytic area S2) as the above bubbling method, when the space velocity s = 1440 (ml / ml·h) meets the conditions. N is the number of active catalyst-supported particles. For catalysts of the same volume, Nv2 = ~ 0.03Vc2 = 0.03Vc1, N = 0.6 (r1 / r2) 3 ;s2=4πr2 2 , v2=4πr2 3 / 3; S2=Ns2=N·4πr2 2, (the comparison of catalysts of the same mass is basically the same); S2: S1 = 0.6 (r1 / r2) ~ = 3.10 5 , when the space velocity s = 1440 (ml / ml·h).

[0225] Comparison: Generally speaking, the catalytic efficiency per unit area of ​​LSACs in the present invention is 10 higher than that of solid supported catalysts. 3 ~10 9 The exceptional efficiency of LSACs depends on the volumetric / mass efficiency and catalytic interfacial area (bubble and droplet methods represent low and high interfacial areas, respectively). Although the volumetric efficiency of bubbling methods may be lower than that of solid-supported catalysts, the advantages of bubbling methods include lower manufacturing costs, longer service life, and lower maintenance costs—the so-called lower lifecycle costs.

[0226] It is clear from the above calculations, and as demonstrated in other embodiments of the present invention, that droplet-based LSACs can provide further overall superior efficiencies.

[0227] Example 4

[0228] The catalytic reaction experimental device is the same as that in Example 1

[0229] LSACs catalyst alloy formula:

[0230] Fe series: 16.7Fe-83.3Ce, 27.5Fe-72.5Sm, 8.5Fe-91.5La

[0231] As before, the alloy was melted before the catalytic experiment began. The loading of each component was measured according to the recipe and bubble column length, then loaded into a graphite crucible. The temperature was raised in stages to 1050°C and held for 12 hours while maintaining an Ar purge. The LSACs catalyst melt was then reduced with hydrogen to the reaction temperature.

[0232] 1) Ethane dehydrogenation EDH. Reaction conditions are the same as in Example 1

[0233] Table 16 Catalytic data of Fe system in ethane dehydrogenation EDH

[0234] Temperature Metal and alloy formulations Ethane conversion rate % Ethylene selectivity% 700 8.5Fe-91.5La 7.69 90.66 700 27.5Fe-72.5Sm 8.37 89.94 700 16.7Fe-83.3Ce 11.24 93.89 750 8.5Fe-91.5La 25.83 93.41 750 27.5Fe-72.5Sm 34.41 87.36 750 16.7Fe-83.3Ce 43.15 89.60

[0235] 2) Ammonia Synthesis. A graphite crucible was used for the ammonia synthesis reaction. Before the catalytic experiment began, the crucible was loaded with the components according to the 16.7Fe-83.3Ce alloy formula and a liquid column measuring length of 150 cm. The crucible was heated to 1050°C and held for 4 hours. Ar gas was purged and then reduced with hydrogen. The reaction gas flow rate was 30 sccm, with a N:H ratio of 1:3.17, at atmospheric pressure and 600°C. The ammonia yield was 0.07%.

[0236] Example 5

[0237] The catalytic reaction experimental device is the same as that in Example 1

[0238] LSACs catalyst alloy formula: Ag system: ethylene / propylene oxidation to EO / PO.

[0239] EO: Ethylene oxidation to EO. Using a high-pressure microreactor, the alloy was melted before the catalytic experiment began. The components were loaded into a crucible according to the following formula and a bubble column length of 150 mm. The temperature was raised in stages to 1050°C and held for 12 hours while maintaining an Ar purge. The LSACs catalyst melt was reduced with hydrogen and then cooled to the reaction temperature. The gas flow rate was 75 sccm, and the composition (mol concentration) was 30% C2H4, 7.5% O2, and 1.55% CO2. N2 was used as the balance gas. 0.1-0.5 ppm of ethylene dichloride (EDC) was introduced into the feed gas. The reaction pressure was 2.06 MPa.

[0240] Table 17 Catalytic data of Ag system in ethylene oxidation to EO

[0241]

[0242] PO: Propylene oxidation to PO. Before the catalytic experiment began, the alloy was melted. The components were loaded into a crucible according to the recipe and a bubble column length of 150 mm. The temperature was raised in stages to 1050°C and held for 12 hours while maintaining an Ar purge. The LSACs catalyst melt was then reduced with hydrogen and cooled to the reaction temperature. The gas flow rate was 30 sccm, and the composition (mol concentration) was 10% C3H6, 10% O2, and 10% H2, with Ar as the balance gas. The reaction pressure was 0.1 MPa.

[0243] Table 18 Catalytic data of Ag system in propylene oxidation to PO

[0244] Temperature Metal and alloy formulations Propylene conversion rate% PO Select 2 Sex 0% 305 18Au-82Bi 16.0 74.8 305 16Au-0.1Fe-83.9Bi 18.7 71.3 305 12Au-88Sn 10.1 77.2 305 12Au-0.1Fe-87.9Sn 12.5 75.6

[0245] Example 6

[0246] The catalytic reaction experimental device is the same as that in Example 1

[0247] LSACs catalyst alloy formula: 2Cu-2Zn-96In

[0248] Methanol from syngas. A micro high-pressure reactor was used for the syngas-to-methanol reaction. Before the catalytic experiment began, the alloy was melted. According to the 2Cu-2Zn-96In formula and a bubble column length of 150 mm, the components were loaded into a crucible, and the temperature was raised in stages to 750°C. The temperature was maintained for 12 hours, while Ar gas was purged. Hydrogen was used for reduction to obtain a LSACs catalyst melt, which was then cooled to the reaction temperature and pressurized for reaction. The gas flow rate was 30 sccm, and the composition (mol concentration) was H2 20%, CO 10%, CO2 10%, with Ar as the balance gas. The reaction temperature was 260°C, and the reaction pressure was 5 MPa. A CO conversion of 46.9%, a CO2 conversion of 53.24%, a methanol selectivity of 76.1%, and a methanol yield of 37.9% were obtained.

[0249] Example 7 (using Figure 3 quartz vent tube shown)

[0250] The catalytic reaction experimental device adopts the form of a top-blown reactor, the heating device is a vertical tube furnace, the reaction vessel is a stainless steel outer sleeve + ceramic crucible, and the reactor introduction device is as follows Figure 3 The quartz vent tube shown in the figure also includes other supporting devices. The reaction vessel is a ceramic tube with an inner diameter of 10 mm. The quartz gas tube has a thick-walled structure, with a wall thickness of 7 mm, i.e., an outer diameter of 9 mm and an inner diameter of 2 mm. A gap is formed between the outer wall of the quartz gas tube and the reaction vessel, serving as a gas outlet. The center of the quartz gas tube serves as an inlet channel, through which gas enters and reacts with the catalyst melt in the reaction vessel.

[0251] The inner diameter ID of the crucible is 10 mm. Before the catalytic experiment begins, the alloy is melted first. The loading amount of each component is measured according to the formula and loaded into the crucible. The temperature is raised to 1050 ° C in stages and kept warm for 12 hours. Ar gas is kept purged and the LSACs catalyst melt is obtained by hydrogen reduction. The melt is cooled to the reaction temperature. The bottom of the crucible is supported and insulated by ceramic insulating materials. Heating and constant temperature are provided by a vertical tube furnace. The quartz vent tube is lowered to 1.5 mm above the melt surface and flush with the upper end of the heating zone. The crucible provides 78.5 mm 2 The catalytic area is 100 nm. The crucible outside the heating zone is exposed to air and kept cool by an external fan. The reactor headspace effect above the melt surface is further corrected by subtracting the data from a blank crucible. The melt temperature is pre-measured using a K-type thermocouple inserted into the melt. The mixed gas is introduced into the reactor from above via a quartz tube using a gas mass flowmeter and analyzed by an online mass spectrometer (MS) and a gas chromatograph (GC).

[0252] 1) SMR methane steam reforming reaction: A mixture of 0.25 sccm methane, 0.25 sccm water vapor, and 2 sccm argon was flowed over the surface. Results were as follows: 20Cu-10Zn-3Al-0.3Ce-66.7In at 850°C, methane conversion was 88.5%; 60Cu-30Zn-9Al-1Ce at 920°C, methane conversion was 99.3%.

[0253] 2) Methanol Steam Reforming: The tube was heated to 150°C, and a mixture of 0.25 sccm of methanol, 0.25 sccm of water vapor, and 2 sccm of argon flowed over the surface. The results were as follows: 20Cu-10Zn-3Al-0.3Ce-66.7In, 580°C, methanol conversion of 98.6%.

[0254] 3) MP methane thermal cracking to produce hydrogen: A mixture of 0.25 sccm methane and 2.25 sccm argon was flowed over the surface. Results: 30Mn-70Bi, reaction temperature 1040°C, hydrogen yield 0.43 sccm. Efficiency remained unchanged over 120 hours.

[0255] When the catalyst used was 27Ni-73Bi:MP, a top-blown reactor was used for the methane pyrolysis hydrogen production reaction, the reaction temperature (1040°C), the reaction gas and flow rates were the same, and the alloy melt was replaced with 27Ni-73Bi, the hydrogen yield was 0.29 sccm. When the catalyst used was 45Cu-55Bi:MP, a top-blown reactor was used for the methane pyrolysis hydrogen production reaction, the reaction temperature (1040°C), the reaction gas and flow rates were the same, and the alloy melt was replaced with 45Cu-55Bi, the hydrogen yield was 0.31 sccm. This shows that under the same conditions, the catalytic efficiency of 30Mn-70Bi is higher than that of 27Ni-73Bi and 45Cu-55Bi, proving that the Mn-Bi alloy is a superior formula combination. Furthermore, the market price of manganese is lower than that of copper and only about one-tenth that of nickel.

[0256] Comparing manganese with nickel and copper: 30Mn-70Bi (hydrogen yield 0.43 sccm) has a higher catalytic efficiency than 27Ni-73Bi (hydrogen yield 0.29 sccm) and 45Cu-55Bi (hydrogen yield 0.31 sccm) under the same conditions, proving that the Mn-Bi alloy is a superior performance combination. Furthermore, the market price of manganese is lower than that of copper and only about one-tenth that of nickel.

[0257] Comparative Example 7:

[0258] The catalyst is metal Ni foil: MP methane thermal cracking hydrogen production reaction: a top-blown reactor is used, the reaction temperature (1040 ° C), the reaction gas and flow rate are the same as in the above embodiment (3), the alloy melt is replaced by a catalytic surface area of ​​3cm 2The metal Ni foil produced 0.12 ml of hydrogen in 2s, and the instantaneous conversion rate per unit catalytic area was close to 100%. However, the hydrogen production rate dropped to 0.3 sccm after 10 minutes and was completely deactivated after 1 hour. It can be observed that the Ni surface was completely covered with carbon.

[0259] Comparison: The MP conversion rate in Comparative Example 7 was instantly higher than that of the 30Mn-70Bi catalyst in this example, but it declined after 10 minutes and was completely deactivated after 1 hour, making it unusable without regeneration. This shows that the catalyst stability of this example is far superior to that of Comparative Example 7, with the cumulative hydrogen yield exceeding that of Comparative Example 7 after 30 minutes.

[0260] Example 8

[0261] The catalytic reaction experimental device is the same as that in Example 1

[0262] LSACs catalyst alloy formulas include Li-Mn-Bi, Li-Mg, 10Na-10Mn-Bi, 10K-10Mn-80Bi, and 50Li-50Ca.

[0263] OCM methane oxidative coupling to ethylene. The OCM methane oxidative coupling reaction uses a graphite crucible. Before the catalytic experiment begins, the alloy is melted. The components are loaded into the crucible according to the recipe and bubble column length. The temperature is then raised in stages to 1050°C and held for 12 hours while maintaining an Ar purge. The catalyst is then reduced with hydrogen to produce a LSACs catalyst melt, which is then cooled to the reaction temperature.

[0264] The reaction gas flow rate is 30 sccm, methane 30%, carbon dioxide 30%, Ar 40%. The catalytic reaction results are as follows:

[0265] Table 19 Catalytic data of catalysts in OCM methane oxidative coupling to ethylene

[0266] Temperature Metal and alloy formulations Methane conversion rate% C2 selectivity % 800 10Li-10Mn-80Bi 26 75 800 50Li-50Mg 15 63 800 10Na-10Mn-Bi 28 76 800 10K-10Mn-80Bi 22 72 800 50Li-50Ca 13 61 800 30Li-10Mn-60Bi 33 79

[0267] Embodiment 9

[0268] The catalytic reaction experimental device is the same as that in Example 1

[0269] LSACs catalyst alloy formula: 0.5Mo-Ga, 1.5Mo-1.5Ni-97Bi, 1.5V-Ga, 31Mn-Sm, 10V-Se, 11.5Fe-Sb.

[0270] MDA methane oxygen-free production of aromatics. The MDA methane oxygen-free production of aromatics reaction was performed in a graphite crucible. The alloy was melted before the catalytic experiment began. The components were loaded into the crucible according to the recipe and bubble column length. The temperature was raised in stages to 1350°C and held for 12 hours while maintaining an Ar purge. The catalyst was then reduced with hydrogen to produce a LSACs catalyst melt, which was then cooled to the reaction temperature. The reaction gas flow rate was 10 sccm, consisting of 30% methane and 70% Ar.

[0271] Table 20 MDA methane to aromatics catalytic data

[0272]

[0273] Example 10 (forming droplets under reaction conditions on a carrier)

[0274] The catalytic reaction experimental device is the same as that in Example 1

[0275] LSACs catalyst alloy formula: 3Ni-1Mo-96Bi; the metal elements come from inorganic salts.

[0276] MTOAH is an oxygen-free direct process for the production of olefins, aromatics and hydrogen.

[0277] The catalyst component precursors are first loaded onto a support (ZSM-5) and calcined to form an alloy. After heating under reaction conditions, the alloy melts on the support, forming droplets due to the surface tension of the catalyst alloy and the support structure. The catalyst component is an inorganic salt, meaning the metal in the alloy formula is derived from the inorganic salt precursor. In-situ high-temperature XRD and in-situ high-temperature energy dispersive spectroscopy of the 3Ni-1Mo-96Bi alloy catalyst at 500°C indicate a liquid state.

[0278] The specific steps include: 1) firstly calculating the concentration and relative atomic mass of the supported metal element according to the formula, and then weighing the metal ion mass of the corresponding mass of the salt: nickel nitrate hexahydrate (Ni(NO3)2·6H2O), ammonium heptamolybdate ((NH4)6Mo7O 24 ) and bismuth nitrate (Bi(NO3)3) are dispersed in a 1% dilute nitric acid solution according to the Ni:Mo:Bi ratio of 3:1:96. 2) The solution is ultrasonically vibrated for 30 minutes, and the above solution is added dropwise to 2 times the mass of ZSM-5 molecular sieve, and stirred evenly for wet impregnation. The above sample is sealed and allowed to stand for aging for 24 hours. 3) It is then placed in an oven at 105°C for 24 hours, and after being evenly ground with a mortar, the above modified catalyst is reduced in a 550°C tubular furnace with H2 for 5 hours, and then ground again after cooling to obtain the ZSM-5 supported metal modified ZSM-5 molecular sieve catalyst Ni 0.03 Mo 0.01 Bi 0.96 / ZSM-5, stored in a stainless steel tank in a sealed and dry place.

[0279] Application (Catalysis): MTOAH methane oxygen-free direct production of olefins, aromatics, and hydrogen: The reactions are conducted in separate quartz crucibles with a total length of 1000 mm. A mass flowmeter (MFC) is used to introduce the mixed feed gases from the top of the crucible through a thin quartz tube. The length of the reaction zone matches the length of the constant-temperature heating zone, which is insulated by a tube furnace heating zone (600 mm long) at the top and bottom and multiple layers of insulation, such as mica, ceramic, and asbestos, at the top and bottom of the crucible (150 mm and 250 mm, respectively). The crucible's top and bottom are exposed to air outside the insulation layer and maintained cool by an external fan to minimize the effects of pure headspace heat. Headspace effects are further corrected using reaction data from selected inert metals. K-type thermocouples in the crucible measure the temperature at multiple points during the reaction. The reaction pressure was set at 0.1 MPa and the reaction temperature was 750°C. After purging, the above-mentioned catalyst powder was sprayed into the experimental device (the 3Ni-1Mo-96Bi alloy on the carrier melted into droplets at this reaction temperature) at a spray rate of 4 g / min. At the same time, 20 sccm of CH4 was introduced as a reaction raw material, resulting in a methane conversion rate of 16.7% and an aromatics selectivity of 97.1%.

[0280] It should be noted that: for the preparation of solid-state supported single-atom catalysts, there is also a similar wet impregnation method as mentioned above, but in order to achieve single-atom dispersion, it is generally necessary to use the so-called "defect engineering", that is, to create defects on the support surface to anchor the active metal. For example, for solid CeO2 supported single-atom Pt catalyst Pt1 / CeO2, ascorbic acid can be used to adsorb on the CeO2 surface to reduce it to produce rich Ce 3+ Subsequently, a weakly reducing surface is used to monodisperse Pt on the CeO2 surface, achieving the construction of a single-atom Pt-CeO2 interface. Similar preparation methods are complex, costly, and limited to laboratory scale. They also suffer from low loading (typically <0.5 wt%) and sintering problems at high temperatures. Compared to the LSACs method in the example, these methods are significantly more expensive, difficult to scale up, have low loading, and exhibit poor stability.

[0281] Example 11

[0282] The catalytic reaction experimental device is the same as that in Example 1

[0283] LSACs catalyst alloy formula: 0.5Ru-0.5La-99Sn, 4Mn-3Fe-3Co-90Bi.

[0284] The metals in the above alloy formula are obtained from a Ru-La mixture and Sn pellets: wherein the Ru-La mixture can also be obtained, for example, by the following method: ruthenium trichloride is fully dissolved in deionized water according to the stoichiometric amount, and then a lanthanum nitrate solution is added and mixed uniformly, and the solution is ultrasonically vibrated for 10 minutes, and then dried at 110°C overnight with stirring, and the product is annealed at 400°C for 4 hours to form a Ru-La mixture.

[0285] The FT synthesis reaction uses a micro high-pressure reactor and a graphite crucible.

[0286] Procedure: The components were loaded into a crucible according to the recipe and a 20cm bubble column length. The temperature was then raised in stages to 1050°C and held for 12 hours while maintaining an Ar purge. The catalyst was then reduced with hydrogen to produce a LSACs catalyst melt, which was then cooled to the reaction temperature. Process conditions were 330°C, 1.2 MPa, H / CO ratio = 2, total flow rate 30 sccm, and H:CO ratio = 1:1.

[0287] Table 20F-T synthesis reaction catalytic data:

[0288]

[0289] Comparative experiments using 4Mn-96Bi and 10Mn-90Bi yielded syngas conversions of 10% and 13%, respectively, significantly lower than the 63% conversion achieved by 4Mn-3Fe-3Co-90Bi. This suggests that adding other transition metals to Mn-based alloys can significantly enhance their activity.

[0290] Example 12

[0291] LSACs catalyst alloy formula: 10Zn-90Mg

[0292] FCC catalytic cracking.

[0293] FCC catalytic cracking reaction uses a quartz crucible. Before the start of the catalytic experiment, the components are loaded into the crucible according to the 10Zn-90Mg alloy formula and the liquid column metering length of 5 cm. The crucible is heated to 650°C and kept at this temperature for 4 hours. Ar gas is purged and the crucible is reduced with hydrogen.

[0294] The crucible is 80 cm long, with the bottom 10 cm heated to 1150°C. The crucible is temperature-controlled in sections, with the top temperature at 100°C. A vent tube is inserted into the 520°C temperature zone (where the Zn-Mg alloy melt primarily resides). Atmospheric residual oil is injected into the Ar gas stream via a quartz syringe. The heavy oil conversion rate reaches a maximum of 94.5%, with dry gas accounting for 1.5% by mass, liquefied petroleum gas 13% by mass, gasoline 49% by mass, diesel 21% by mass, slurry oil 9.63% by mass, and coke 8% by mass.

[0295] Example 13

[0296] The catalytic reaction experimental device is the same as that in Example 1

[0297] LSACs catalyst alloy formula: 8Mn-8Li-84Bi

[0298] Ammonia synthesis. A quartz crucible was used for the ammonia synthesis reaction. Before the catalytic experiment began, the crucible was loaded with the components according to the 8Mn-8Li-84Bi alloy formula and a liquid column length of 30 cm. The crucible was heated to 1050°C and held for 4 hours. Ar gas was purged and then reduced with hydrogen. The reaction gas flow rate was 30 sccm, with an N:H ratio of 1:3.17, at atmospheric pressure and 500°C. The ammonia yield was 0.11%.

[0299] The control experiments of 8Mn-92Bi and 18Mn-82Bi showed that the ammonia yields were 0% and 0.01% respectively. By comparison, it was found that adding other transition metals to Mn-based alloys can greatly improve their activity.

[0300] Example 14

[0301] The catalytic reaction experimental device is the same as that in Example 1

[0302] LSACs catalyst alloy formula: 23.5Ni-76.5Ce, 35Ni-65Ce, 23.5Ni-76.5Ce, 35Ni-65Ce

[0303] Lignin conversion. The hydrogenolysis reaction of diphenyl ether (DPE), a representative component, was used as an example. Before the catalytic experiment began, the alloy was melted. The loading of each component was measured according to the recipe and a bubble column length of 20 cm, then placed into a quartz crucible. The temperature was raised in stages to 1050°C and held for 12 hours, maintaining an Ar purge. The LSACs catalyst melt was then reduced with hydrogen to the reaction temperature.

[0304] The pipeline was heated to 150°C, and 5 sccm of diphenyl ether and 5 sccm of argon were introduced. The generated gas passed through the 150°C heated pipeline to the GC-MS gas chromatography-mass spectrometry analysis. The results are as follows:

[0305] Table 21 Catalytic data of nickel-based catalysts in lignin conversion

[0306]

[0307] Example 15

[0308] The catalytic reaction experimental device is the same as that in Example 1

[0309] LSACs catalyst alloy formula: 1.5Ni-1.5Cu-97Bi, 19.9Au-81.1Bi

[0310] Acetylene hydrogenation. Before the catalytic experiment began, the alloy was melted. The components were loaded into a quartz crucible according to the recipe and a bubble column length of 20 cm. The temperature was raised in stages to 1050°C and held for 12 hours. Ar was maintained as a purge, and the LSACs catalyst melt was reduced with hydrogen. The melt was then cooled to the reaction temperature. The flow rate of the reaction gas (1% C2H2, 20% C2H4, 10% H2, He balance) was 30 sccm. The results are as follows:

[0311] Table 22 Catalytic data in acetylene hydrogenation

[0312] Temperature Metal and alloy formulations Acetylene conversion rate% Ethylene selectivity% 300 1.5Ni-1.5Cu-97Bi 87 96 300 19.9Au-81.1Bi 53 70 350 1.5Ni-1.5Cu-97Bi 98 91 350 19.9Au-81.1Bi 72 55

[0313] Example 16 (Reactant is solid fine powder)

[0314] The catalytic reaction experimental device is the same as that in Example 1

[0315] LSACs catalyst alloy formula: 5Ni-95Bi, 3Ni-6Mn-3Al-88Bi, 92.2Zn-17.8Mg, 5Ni-25Mn-70Bi.

[0316] Plastic recycling

[0317] Before the catalytic experiment begins, the alloy is melted. The components are loaded into a quartz crucible according to the recipe and a bubble column length of 20 cm. The temperature is then raised in stages to 1050°C and held for 12 hours while maintaining an Ar purge. The LSACs catalyst melt is then reduced with hydrogen to the reaction temperature. Reactant introduction: Before the reaction, waste plastic is pulverized and then introduced into the bottom of the crucible simultaneously with air or water vapor.

[0318] 1) Production of hydrogen and CNTs

[0319] Formula 5Ni-95Bi, 60mg of plastic 50% PP + 50% HDPE fine powder was introduced into 100sccm nitrogen per minute, the reaction temperature was 800℃, and the product was 33% solid carbon, of which 20% was CNT; 54% gaseous product, of which 11% was hydrogen.

[0320] Formula 3Ni-6Mn-3Al-88Bi, 60mg of plastic PP fine powder was introduced into 100sccm of nitrogen per minute, the reaction temperature was 800℃, and the product was 51% solid carbon, of which 39% was CNT+graphene; and 38% gaseous product, of which 8% was hydrogen.

[0321] 2) Production of hydrocarbons and oil

[0322] Formula 92.2Zn-17.8Mg (melting temperature 800°C), 60mg of plastic PS fine powder was introduced into 100sccm of nitrogen per minute, the reaction temperature was 450°C, and the product was 2.5% toluene, 1.2% ethylbenzene, and 49% styrene.

[0323] 3) Production of synthesis gas

[0324] Formula 5Ni-25Mn-70Bi, 30mg plastic PP fine powder HDPE + 30ml water vapor are introduced by 100sccm nitrogen per minute, the reaction temperature is 850℃, the conversion rate is 95%, and the product is hydrogen-rich synthesis gas and a small amount of carbon deposits.

[0325] Example 17 (Evaporation and atomization of droplets and reflux catalysis of low-boiling-point element liquid-phase single-atom catalyst)

[0326] LSACs catalyst alloy formula: Mg, 10Zn-90Mg

[0327] Catalytic reaction experimental equipment Figure 2 As shown, the heating device includes a vertical tubular furnace with a bottom filled with quartz sand and an auxiliary heating device thereon; the main reactor is a quartz crucible with a total length of 1000 mm and a diameter of 25 mm, and also includes other supporting devices.

[0328] like Figure 2 As shown, from bottom to top: the bottom metal and alloy section is heated to 1150℃ by a tube furnace and kept warm, with a heating zone of 150mm, so that Mg and Mg-Zn alloy evaporate. The middle and upper middle sections are respectively set up with two sections, 700-1000℃ in the middle and 680-700℃ in the upper middle to prevent the metal and alloy from solidifying. Multi-point temperature measurement is carried out at the top, middle and bottom. The top 200mm crucible is exposed to the air and is kept cool by an external fan in the air. Figure 2 As shown, insulating quartz beads are placed between the air-cooled and upper-middle regions to create temperature zones, where only a negligible amount of metal vapor rises to the quartz beads and avoids the air-cooled areas. When the temperature drops below 907°C, Mg and Zn condense into liquids, with numerous droplets forming a thin mist in the reaction zone. These droplets reflux and suspend under the combined effects of gravity and the rising hot air flow. Finally, they descend from the upper cooling zone below the insulating quartz beads to the bottom high-temperature zone, where they are evaporated. Low-boiling-point elements, through continuous evaporation, condense, and atomize, form reflux droplets, which suspend in the main reaction zone in the middle of the reactor vessel.

[0329] The mixed gas was introduced into the reactor from above via a pipeline using a gas mass flowmeter (MFC) for analysis using an online mass spectrometer (MS) and a gas chromatograph (GC). The crucibles were loaded with 10Zn-90Mg and Mg, respectively. The alloy loading height was 50 mm (Mg ~25g, 10Zn-90Mg ~31g).

[0330] (1) Methane thermal cracking to produce hydrogen and co-produce graphene and CNTs. The reaction feed gas volume was 600 sccm, with a methane / hydrogen ratio of 1:1. Vent tubes were inserted into the bottom of the crucible at 950°C, 1000°C, and 1150°C, respectively. The reaction time was 2 h. The reaction results are as follows:

[0331] Table 23 Catalytic data of graphene and CNT in the co-production of hydrogen from methane pyrolysis

[0332]

[0333] After the reaction, the solid powder was pressed into blocks and then evaporated at 1200°C for demetallization. SEM and TEM analysis revealed the remaining product to be a highly crystalline nanocarbon product—a mixture of carbon nanotubes and graphene. Further reducing the metal Mg to 10 mm resulted in a decrease in conversion of less than 1%, indicating that the catalytic area generated by the reduced catalyst atomization and condensation droplets was already sufficient for catalytic efficiency. The primary influencing factors were uneven atomization and airflow, as well as mass transfer limitations.

[0334] (2) n-Butane and carbon dioxide coupling to produce BTX and light hydrocarbons.

[0335] The crucible was loaded with 90Zn-10Mg, with a total alloy mass of 2g. The reaction gas flow rate was 60sccm, with a CO2 / n-butane ratio of 0.95. Vent tubes were inserted into the crucibles, and the temperature was 550°C. The reaction lasted for 10 hours. Results: CO2 conversion of 33%, n-butane conversion of 99%, and aromatics selectivity of 87%.

[0336] Comparative Example 8:

[0337] The Mg loading was measured according to the length of the bubble column (16 cm) and loaded into a quartz crucible. The temperature was raised to 1050°C in stages and held for 2 hours. Ar gas was maintained and the Mg catalyst melt was reduced with hydrogen. The melt was cooled to a reaction temperature of 950°C. The reaction raw gas volume was 10 sccm, with a methane / hydrogen ratio of 1:1. A vent tube was inserted into the bottom of the crucible, resulting in a methane conversion rate of 33.8% and a reaction time of 12 hours. After the reaction was completed, the metal was evaporated at a high temperature of 1200°C. The remaining product was analyzed by SEM and TEM to be a mixture of highly crystalline nanocarbon products, but only 3.4% of the carbon yield of the above examples was obtained.

[0338] Comparison: The volume / mass efficiency of the atomized condensation droplet catalysis of Example 17 is 10 higher than that of the bubbling method catalysis of the comparative example. 4 times.

[0339] In addition, the efficiency of the droplet method is calculated according to conventional methods of those skilled in the art. The droplet diameter is 20 μm, and the diffusion coefficient in the gas is generally 10 -5 ~10 -4 m2 / s range, take 0.1-0.3cm 2 / s, take 0.2cm 2 / s, and each droplet can catalyze 0.0084ml / s of raw materials per second (average diffusion radius 0.126cm / s), and the corresponding catalyst volume is 4*10 -9 ml, the difference between the two is 2.1*10 6 Even if we consider the mass transfer efficiency of 0.25, because the heating and reaction volume increase by 8 times, the droplet method can catalyze ~10 6 ml cold raw gas / ml catalyst·s. This is also confirmed by the above comparison.

[0340] Comparative Example 9:

[0341] BTX and light hydrocarbons were prepared by coupling n-butane with carbon dioxide. The HZSM-5 sample was calcined at 600°C in a muffle furnace for 5 hours, and then sliced, crushed and sieved to 40-60 mesh for reaction evaluation. 0.4 g of the prepared catalyst (zinc supported on a molecular sieve carrier) was loaded into a stainless steel fixed bed reactor containing a quartz tube (6 mm id). n-Butane and carbon dioxide gases controlled by a seven-star mass flowmeter were introduced into the catalyst bed. The reaction temperature was 500°C. The contact time was changed by adjusting the catalyst weight (0.025-0.8 g), while keeping other reaction conditions constant. The mass space velocity of n-butane was ~0.1 h -1 Under the optimized reaction conditions, when the CO2 / n-butane ratio was 0.475, the conversion of CO2 and n-butane reached 17.5% and 100%, respectively, with an aromatics selectivity of 80%.

[0342] Comparison: Using a low-cost catalyst and simple equipment, with comparable residence times, this example achieved higher n-butane mass space velocity, CO2 conversion, n-butane conversion, and aromatics selectivity than Comparative Example 9. Because carbon deposits do not affect catalysis, the stability of this example is significantly superior to that of the comparative example. Even in larger-scale equipment, carbon deposits can be easily removed.

[0343] Example 18 (Alloy formed by metal and non-metal)

[0344] The catalytic reaction experimental device is the same as that in Example 1

[0345] LSACs catalyst alloy formula: 20S-80Bi, 2Cr-98Se, 1.5Cr-98.5Te

[0346] EDH. The reaction conditions and alloy melt refining were essentially the same as in Example 1. The 20S-80Bi alloy refining method involved heating the measured elements at 500°C for 4 hours in a sealed quartz tube. S first vaporized and then alloyed with Bi. The alloy was removed and placed in a reaction crucible with a filling height of 50 mm. The catalytic reaction results at 750°C were as follows:

[0347] Table 24 Catalytic data of EDH

[0348]

[0349] Example 19

[0350] LSACs catalyst alloy formula: 40S-60Se

[0351] Nitrobenzene to make aniline.

[0352] Experimental study on the reduction of nitrobenzene to aniline using CO / H₂O catalyzed by sulfur and selenium. The catalytic reaction experimental setup utilized a vertical tube furnace, an 80 cm long stainless steel crucible, and other supporting equipment. The crucible was loaded with S and Se, respectively, in measured quantities of 40S and 60Se, to a height of 10 cm. The bottom 15 cm of the crucible was heated to 250°C and held in the tube furnace. The heated zone (15 cm) allowed for the evaporation of S and Se. Two auxiliary electric heating sections at 220-240°C were installed in the middle and upper middle sections, respectively. Temperatures were measured at multiple points at the top, middle, and bottom sections. The feed gas inlet was positioned in the middle of the measured temperature range. The top 20 cm of the crucible was exposed to air and maintained cool by an external fan. The mixed gas was introduced into the reactor from above via a pipeline using a mass flowmeter (MFC) for analysis by an online mass spectrometer (MS) and a gas chromatograph (GC).

[0353] Dinitrobenzene (1 mmol / min) and pure water (1 mmol / min) were continuously introduced into a quartz crucible reactor with an initial CO atmosphere through a pipeline heated to 215°C, along with 50 sccm of CO. After 30 minutes, the exhaust gas collected from the 215°C pipeline was pumped back into the reactor via a high-temperature pipeline and allowed to react for 2 hours. Aniline content was determined using a gas chromatograph with an FID detector, column temperature of 150°C, and vaporizer temperature of 250°C. Nitrobenzene conversion and aniline yield were 95.6% and 81.3%, respectively.

[0354] It can be seen that the formula of the liquid-phase single-atom catalyst of the present invention can be composed of at least one metal element, or can be composed of at least two elements of non-metallic sulfur, selenium, and tellurium, such as S-Se mentioned in this embodiment.

[0355] Example 20

[0356] The reaction conditions and alloy melt refining were the same as in Example 1. The reaction pressure was set at 0.1 MPa. After purging and pretreatment, the experimental apparatus was introduced with 30 sccm of the reaction feedstock (feed ratio: 47% CH₄, 23% CO₂, 30% Ar). The catalytic performance of each catalyst at a reaction temperature of 1080°C was evaluated in a 150 mm bubble column, including methane and carbon dioxide conversions, and hydrogen and carbon monoxide yields. The results are shown in Table 25.

[0357] Table 25 Catalytic data of DRM

[0358]

[0359] Two elements generally considered inert, Bi and In, can exhibit good catalytic performance after forming Bi-In alloys, reflecting that multiple active centers in LSACs can enhance and change the reaction mechanism by binding intermediates, forming the so-called co-catalytic interaction.

[0360] Example 21

[0361] Anti-poisoning experiment.

[0362] Anti-S poisoning experiments of Mn-series A1, A2, A3, Ni-series B1, B2, Pt-series C1, and Fe-series catalysts.

[0363] In Examples 1, 2, and 3, small amounts of sulfur were added, and it was found that each catalyst was resistant to sulfur poisoning. Increased sulfur content in Fe-based catalysts can be restored after desulfurization with alkaline slagging materials or an oxidant. In the aforementioned examples, the addition of sulfur to the reactions did not affect catalytic efficiency or stability.

[0364] Experiments have shown that Mn-based catalysts A1, A2, and A3, Ni-based catalysts B1 and B2, and Pt-based catalysts C1 are all resistant to poisoning by CO, CO₂, and water. Similarly, the addition of CO, CO₂, and H₂O to reactions unrelated to the original reaction conditions did not affect catalytic efficiency or stability.

[0365] Example 22

[0366] The electronic properties of molten alloys, namely the Bader charge, are calculated using ab initio molecular dynamics at room temperature.

[0367] The liquid surface area is One Mn atom was added to the 80 Bi atoms in the sample. Ab initio, isothermal, and molecular dynamics (AIMD) simulations were performed using the VASP simulation package with density functional theory (DFT) forces. The Bader charge was calculated using the Henkelman algorithm by subtracting the pseudopotential (PAW) explicit electrons from the integrated electron density within the Bader volume.

[0368] Calculation results: Mn atoms carry a fractional negative charge, Bi atom clusters carry a fractional positive charge, the average charge of Mn is -0.3 to -0.8, and Bi atom clusters carry a corresponding positive charge. The same method is used to calculate the liquid surface area of Two Mn atoms were added to a total of 80 Bi atoms. Calculations showed that the Mn atoms were negatively charged, while the Bi clusters were positively charged. The average Mn charge ranged from -0.2 to -0.7, and the Bi clusters carried a correspondingly positive charge. The absolute value of the charge correlated with the catalytic activity measured in the EDH experiment: the smaller the absolute value of the positive and negative charges, the higher the activity.

[0369] The above method is also used to calculate the molten binary alloys of transition metals Ti, V, Cr, Fe, Co, Ni, Cu, Zn, Ru, Ag, Pt, Au, rare earth metals La, Ce, alkali metals Li, Na, K, alkaline earth metals Mg, Ca, and metal Al, and p-electron metals Ga, In, Sn, Pb, Bi, rare earth metals La, Ce, and Sm as the second element. It is also found that the atoms of the first elements (Ti, V, Cr, Fe, Co, Ni, Cu, Zn, Ru, Ag, Pt, Au, La, Ce, Li, Na, K, Mg, Ca, Al) are negatively charged, and the atomic clusters of the second elements (Ga, In, Sn, Pb, Bi, La, Ce, Sm) are positively charged.

[0370] Experiments show that at least some of the elements in the above-mentioned molten binary alloy are in a quasi-ionic and associated monatomic state; this quasi-ionic and associated monatomic state refers to the "short-range ordered" cluster structure of the liquid, in which several pairs of cluster components are subjected to the combined action of van der Waals forces, thermal motion, fluctuations, and mobile collisions, the valence bonds are broken, one cluster of a pair of clusters is dissociated, the element is ionized and associated monatomic, and the single anion / or cation formed corresponds to the cation / anion group formed by the other cluster component, and then recombine to form a cluster component pair; during the period from cluster dissociation and ionization and associated monatomic to recombination, this part of the elements presents a single ionic state and a discrete state of associated monatomic in the liquid, and together with the corresponding other molecular ion cluster, becomes a catalytic active center.

[0371] This quasi-ionic and associated monatomic state is reflected in the Bader charge calculations: 1) Some elements and corresponding clusters are ionized and thus charged. In particular, contrary to common perception, active elements (such as Mn, Ni, Cu, and Pt) are negatively charged, while inert cluster components (In, Sn, and Bi) are positively charged. 2) The fractional charges (i.e., non-integer charges) carried by some elements and corresponding clusters indicate transient quasi-ionic properties; 3) The absolute value of the charge correlates with experimentally measured catalytic activity: the smaller the absolute value of the positive and negative charges, the higher the activity.

[0372] Due to the above-mentioned microscopic mechanism, single ions, accompanying single atoms / free radicals, and corresponding molecular ion clusters in the reaction process all directly participate in catalysis, enhancing and changing the reaction mechanism by binding to intermediates, forming the so-called co-catalytic interaction.

[0373] Based on the similarity of elemental properties, those skilled in the art can perform the same calculations for all other combinations, identify the transient ionization of some elements from the fractional Bader charge, and confirm that the relevant combinations have LSACs characteristics.

[0374] Example 23

[0375] Experiment on abnormal resistivity of metal alloy melt.

[0376] Liquid-phase single-atom catalysts exhibit anomalous resistivity characteristics that differ from those of solid alloys. The resistance-temperature curve of the alloy melt was measured using a molten alloy four-electrode resistivity measurement device, comprising a nanovoltmeter, a constant current source, a tubular heating furnace, a quartz crucible, a thermocouple, a high-purity W wire electrode, and a data acquisition system. The results are as follows:

[0377] 1) Cu-Sn alloys. At 800-1100°C, 85Cu-15Sn, 80Cu-20Sn, 75Cu-25Sn, and 70Cu-30Sn all exhibit negative resistivity-temperature curves. That is, in the Cu content range of 70-85 at.%, the melt exhibits a negative TCR curve (i.e., resistivity decreases as temperature increases). At 900°C, the resistivity of 80Cu-20Sn is higher than that of 75Cu-25Sn, and that of 75Cu-25Sn is higher than that of 70Cu-30Sn. Because the resistivity of Sn is more than six times that of Cu, this deviates significantly from the approximate law of solid alloy resistivity (more Cu yields lower alloy resistivity) and does not follow the Matthiessen-Nordheim law, resulting in an anomaly.

[0378] 2) Cu-Sb alloys. At 700-900°C, 80Cu-20Sb, 75Cu-25Sb, and 70Cu-30Sb all exhibit negative resistivity-temperature curves. That is, within the Cu content range of 70-80 at.%, the melt exhibits a negative TCR curve. At 750-850°C, within the Cu content range of 30-75 at.%, the alloy resistivity increases with increasing Cu content. Because the resistivity of Sb is 23 times that of Cu, this deviates significantly from the approximate law of solid-state alloy resistivity (more Cu results in lower alloy resistivity) and does not follow the Matthiessen-Nordheim law, resulting in an anomaly.

[0379] 3) Zn-Sb alloys. 25Zn-75Sb exhibits a negative resistivity-temperature curve at 550-750°C; 40Zn-60Sb exhibits a negative resistivity-temperature curve at 525-825°C; 50Zn-50Sb exhibits a negative resistivity-temperature curve at 575-850°C; 60Zn-40Sb exhibits a negative resistivity-temperature curve at 600-800°C; and 80Zn-20Sb exhibits a negative resistivity-temperature curve at 575-625°C. At 600-800°C, within the Zn content range of 40-60 at.%, the alloy resistivity increases with increasing Zn content. Because the resistivity of Sb is 7.5 times that of Zn, this significantly deviates from the approximate law of solid-state alloy resistivity (more Cu results in lower alloy resistivity) and does not conform to the Matthiessen-Nordheim law, resulting in an anomaly.

[0380] It is well known that the resistivity of solid alloys increases with increasing temperature, and the resistivity of alloys is approximately ρ = ∑k i ρ i , where k i =m i / m,k i is the ratio of the mass of a substance to the total mass, ρ i The resistivity of a substance. Further, according to the Matthiessen and Nordheim law, the resistivity of a binary / multinary alloy can be written as: ρ = cρ A +(1-c)ρ B +c(1-c)ρ R ; Where c is the concentration of component A in the alloy, ρ A and ρ B are the resistivities of pure components A and B, respectively, c(1-c)ρ R is the residual resistivity, ρ R is the Nordheim coefficient. It decreases approximately with the increase of the low-resistivity metal content. Similarly, general alloy melts inherit the physical characteristics of solids, and the resistivity increases with increasing temperature and decreases with increasing low-resistivity metal content. The negative resistivity temperature coefficient of some alloy melts can be explained by Faber and Ziman's liquid binary alloy resistivity theory, but the anomaly of this embodiment exceeds the scope of explanation of Faber and Ziman's liquid binary alloy resistivity theory. Ionic liquids, including ionic compound melts, have a resistivity that decreases with increasing temperature; and since conventional observations and existing theoretical models believe that the above-mentioned alloy melts are not ordinary ionic liquids, this embodiment shows that at least some of the elements in the above-mentioned molten binary alloy are in a quasi-ionic state, and this transient ionization becomes the source of single-atom catalytic activity.

[0381] The description of the present invention has been presented for purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the form disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles of the invention and its practical application and to enable those skilled in the art to understand the invention and design various embodiments with various modifications as are suited for specific applications.

Claims

1. A liquid-phase single-atom catalyst for heterogeneous catalysis that can be produced on a large scale, characterized in that: The liquid-phase single-atom catalyst is in a liquid state in which all material components dissolve in each other under reaction conditions, and is used to directly carry out interfacial contact catalytic reaction with reactants; The liquid-phase single-atom catalyst has a chemical composition comprising at least two elements selected from transition metals, metals with p-electron outer layers, rare earth metals, alkali metals, alkaline earth metals, metallic aluminum, and non-metallic sulfur, selenium, and tellurium; the chemical composition is obtained from material components, which are one or more of a mixture, a single substance, and an inorganic compound.

2. The liquid-phase single-atom catalyst according to claim 1, characterized in that The liquid-phase single-atom catalyst has at least one chemical component element that exists in a transient quasi-ionic state in the liquid.

3. The liquid-phase single-atom catalyst according to claim 2, characterized in that The quasi-ionic state of the liquid-phase single-atom catalyst is manifested in the presence of non-integer Bader charges of at least two elements; for liquid-phase single-atom catalysts with different chemical compositions but at least one identical element, or for liquid-phase single-atom catalysts with the same chemical composition but different contents, the smaller the absolute value of the Bader charge, the higher the catalytic activity; wherein the Bader charge is obtained by subtracting the explicit electrons of the pseudopotential from the integrated electron density within the Bader volume when calculating the electronic properties of the molten alloy using quantum mechanics ab initio molecular dynamics.

4. The liquid-phase single-atom catalyst according to claim 2, characterized in that The quasi-ionic state of the liquid-phase single-atom catalyst is also characterized by an anomalous characteristic different from the resistivity of the solid alloy; the catalytic efficiency per unit catalytic area of ​​the liquid-phase single-atom catalyst is higher than that of the non-single-atom alloy catalyst by 10 3 ~10 8 times.

5. The liquid-phase single-atom catalyst according to any one of claims 2 to 4, characterized in that: The liquid-phase single-atom catalyst is in a liquid state in which all material components dissolve in each other under the reaction conditions, and is achieved by: dissolving into a liquid state at room temperature before the reaction, heating and melting into a liquid state before the reaction, or heating and melting into a liquid state under the reaction conditions.

6. The liquid-phase single-atom catalyst according to any one of claims 2 to 4, characterized in that: The liquid-phase single-atom catalyst is used for catalysis in direct interface contact with reactants without adding other reagents.

7. The liquid-phase single-atom catalyst according to claim 1, characterized in that The transition metals include titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, yttrium, niobium, molybdenum, ruthenium, silver, cadmium, tungsten, rhenium, platinum, gold, and mercury; the metals with p electrons in the outer layer include gallium, indium, tin, antimony, lead, and bismuth; the rare earth metals include lanthanum, cerium, praseodymium, neodymium, samarium, and europium; the alkali metals include lithium, sodium, potassium, rubidium, cesium, and francium; and the alkaline earth metals include magnesium and calcium.

8. The liquid-phase single-atom catalyst according to claim 7, characterized in that The chemical composition of the liquid-phase single-atom catalyst is at least two elements selected from the group consisting of metal gallium, indium, tin, antimony, lead, and bismuth, each of which has a p-electron outer layer.

9. The liquid-phase single-atom catalyst according to claim 7, characterized in that The liquid-phase single-atom catalyst has a chemical composition comprising a first element and a second element, and the proportion of the second element is not less than 35%; wherein the second element is at least one element selected from metals with p electrons in the outer layer, such as gallium, indium, tin, antimony, lead, bismuth, rare earth metals lanthanum, cerium, and samarium; and the first element is at least one element selected from transition metals, such as titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, molybdenum, ruthenium, silver, platinum, gold, alkali metals, lithium, sodium, potassium, alkaline earth metals, magnesium, calcium, and metal aluminum.

10. The liquid-phase single-atom catalyst according to claim 9, characterized in that The first element is at least two selected from transition metals titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, molybdenum, ruthenium, silver, platinum, gold, alkali metals lithium, sodium, potassium, alkaline earth metals magnesium, calcium, and metal aluminum.

11. The liquid-phase single-atom catalyst according to any one of claims 9 to 10, characterized in that: The first element is selected from transition metals such as manganese, nickel, platinum, iron, silver, and ruthenium.

12. The liquid-phase single-atom catalyst according to any one of claims 9 to 10, characterized in that: The first element includes metallic manganese.

13. A heterogeneous catalytic method using the liquid-phase single-atom catalyst according to any one of claims 1 to 12, characterized in that: Under reaction conditions, the liquid-phase single-atom catalyst and the reactants undergo an interfacial contact catalytic reaction. After the reaction, the product, unreacted products and by-products are separated from the liquid-phase single-atom catalyst by density difference, and the separation continues during the reaction so that the catalyst at the catalytic interface maintains reaction activity for a long time; wherein, under the reaction conditions, the reactants are a mixture of one or more of gas, solid and liquid that is immiscible with the liquid-phase single-atom catalyst.

14. The heterogeneous catalysis method according to claim 13, characterized in that: The multi-phase catalytic method also includes: when the reactant is a gas, the liquid-phase single-atom catalyst is used as the continuous phase, the gaseous reactant enters the continuous phase in the form of bubbles, and undergoes an interfacial contact catalytic reaction with the liquid-phase single-atom catalyst; when the reactant is a solid, the liquid-phase single-atom catalyst is used as the continuous phase, the reactant enters the continuous phase in the form of particles, is suspended and / or dispersed in the continuous phase, and undergoes an interfacial contact catalytic reaction with the liquid-phase single-atom catalyst; when the reactant is a liquid, the reactant is introduced below the liquid surface of the liquid-phase single-atom catalyst to undergo an interfacial contact catalytic reaction.

15. The heterogeneous catalysis method according to claim 13, characterized in that: The liquid-phase single-atom catalyst performs an interfacial contact catalytic reaction with reactants in the form of liquid droplets.

16. The heterogeneous catalysis method according to claim 15, characterized in that: The heterogeneous catalysis method includes: introducing a liquid-phase single-atom catalyst into a reaction container in the form of droplets by atomization; or forming droplets of the liquid-phase single-atom catalyst in the reaction container by heating, evaporation, and recondensation.

17. The heterogeneous catalysis method according to claim 15, characterized in that: The heterogeneous catalytic method comprises: pre-preparing the liquid-phase single-atom catalyst or a material component providing the chemical composition of the liquid-phase single-atom catalyst into an ultrafine powder, spraying the ultrafine powder into a reactor, and heating it under reaction conditions to form liquid droplets; Alternatively, the heterogeneous catalytic method includes: first pre-loading a substance component that provides the chemical composition of the liquid-phase single-atom catalyst on the surface of a solid support to obtain a support-supported solid alloy catalyst; then introducing the support-supported solid alloy catalyst into a reactor, and under reaction conditions, heating and melting the substance component on the surface of the solid support into droplets to form a liquid-phase single-atom catalyst supported on the solid support; Among them, the step of pre-loading the material components that provide the chemical composition of the liquid-phase single-atom catalyst on the surface of a solid carrier to obtain a carrier-loaded solid alloy catalyst includes: mixing the metal source of the material components, the carrier and the solvent to obtain a suspension; filtering the suspension and then drying it to obtain a precursor; calcining the precursor and then performing a reduction reaction in a reducing gas atmosphere to obtain a carrier-loaded solid alloy catalyst; the carrier-loaded solid alloy catalyst is introduced into the reactor by directly spraying it into the reactor or pre-filling it in the reactor in a fixed bed manner.

18. The heterogeneous catalysis method according to any one of claims 15 to 17, characterized in that: The heterogeneous catalytic method further includes: collecting the catalyst and separating it from impurities for reuse, wherein the catalyst refers to the droplets falling to the bottom of the reaction container after the reaction and / or the powder after cooling.

19. The heterogeneous catalysis method according to claim 15, characterized in that: The liquid-phase single-atom catalyst is a low-boiling-point liquid-phase single-atom catalyst, and its chemical composition includes at least two low-boiling-point elements selected from the group consisting of transition metal mercury, zinc, alkali metal lithium, sodium, potassium, rubidium, cesium, and alkaline earth metal magnesium. The liquid-phase single-atom catalyst in the reaction container is formed into droplets by heating, evaporating, and then condensing, comprising the following steps: The reaction vessel is divided into the following zones in the height direction: the bottom high-temperature zone, the middle main reaction zone and the upper cooling zone; The liquid heterogeneous catalyst is added to the bottom high-temperature zone of the reaction vessel, and the low-boiling-point elements in the liquid heterogeneous catalyst are heated to form low-boiling-point element vapor. The low-boiling-point element vapor rises to the middle main reaction zone and the upper cooling transition zone, condenses and atomizes into droplets, and refluxes and suspends under the combined action of gravity and the rising hot air flow. When it finally falls from the upper cooling zone to the bottom high-temperature zone, it is evaporated by the bottom high-temperature zone again. The low-boiling-point elements are continuously evaporated, condensed and atomized to form reflux droplets and are suspended in the middle main reaction zone of the reaction vessel. The gaseous reactants are introduced into the middle main reaction zone and fully contacted with the reflux suspension droplets to cause a catalytic reaction.

20. The heterogeneous catalysis method according to claim 14, characterized in that: The heterogeneous catalytic method further includes: inserting an electrode into the liquid-phase single-atom catalyst and conducting or plasma-treating the gaseous reactants; And / or, the heterogeneous catalytic method further includes: mixing the solid catalyst particles with the gaseous reactants and bubbling them into the liquid single-atom catalyst continuous phase, wherein the gaseous reactants simultaneously undergo a catalytic reaction with the liquid single-atom catalyst and the solid catalyst encapsulated in the bubbles.

21. The heterogeneous catalysis method according to claim 14, characterized in that: Before heterogeneous catalysis, it also includes: selecting liquid-phase single-atom catalysts based on the absolute value of Bader charge, Selecting a liquid-phase single-atom catalyst according to the absolute value of the Bader charge includes: determining the chemical composition of the liquid-phase single-atom catalyst according to the absolute value of the Bader charge, and determining the ratio of each element in the chemical composition according to the absolute value of the Bader charge.

22. Use of the liquid-phase single-atom catalyst according to any one of claims 1 to 12, characterized in that: The invention is applied to any reaction process of dehydrogenation reaction, hydrogenation reaction, olefin hydroformylation reaction, ammonia-related reaction, petroleum refining catalytic reaction, biomass catalytic utilization, organic pollutant treatment and polymer material regeneration, wherein the dehydrogenation reaction is methane thermal cracking, methane dry reforming, methane steam reforming, methane coupling to ethylene, methane oxygen-free coupling to aromatics, ethane dehydrogenation / oxidative dehydrogenation, propane dehydrogenation / oxidative dehydrogenation, C4 and above alkane dehydrogenation and oxidative dehydrogenation, ethylbenzene dehydrogenation, butane carbon dioxide coupling to light aromatics, aromatic hydrocarbons, polyolefins or asphalt thermal cracking reaction; the hydrogenation reaction is olefin hydrogenation or acetylene hydrogenation; the ammonia-related reaction is ammonia decomposition, ammonia synthesis, ammonia oxidation, nitrobenzene to aniline or SCR denitrification reaction.

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